GEMSTONE TESTING APPARATUS

The application relates to an apparatus for testing gemstones, such as simulant, diamond, and moissanite.

Diamond includes a native crystalline carbon that is very hard. The diamond can have colour or be colourless. When the diamond is transparent and free from flaws, it is highly val ued as a jewellery. It is often used industrially as an abra sive .

Moissanite refers to a silicon carbide mineral and to its var ious crystalline polymorphs. The silicon carbide mineral can be found in nature, although this is rare. It can also be syn thesized in the laboratory.

Synthetic moissanite, which is colourless or near-colourless, resembles diamond in many aspects, such as visual characteris tics, hardness, and thermal conductivity among other physical properties. Therefore, synthetic moissanite is widely used as a diamond simulant in today's jewellery market.

A gemstone tester is often considered as a convenient tool for identifying gemstone, such as diamond, moissanite, and other precious stones. The gemstone tester can include a testing probe for determining thermal conductivity or electrical con ductivity of the gemstone in order to classify the gemstone according to the thermal and electrical conductivity.

Prior art document US 20160363576 A1 discloses a multi-func tional precious stone testing apparatus. The apparatus in cludes a portable housing, a testing unit, and an indication unit. The portable housing includes a hand-held casing and a probe casing. The probe casing extends from a front end of the hand-held casing. The testing unit includes a conductive probe. The conductive probe has a testing end portion that ex tends out of a tip end of the probe casing. The indication unit includes a LED light unit. The LED light unit is placed in the hand-held casing. The LED light unit is also positioned away from the tip end of the probe casing. Functionally, the conductive probe is intended for contacting a testing object to determine a conductivity of the testing object. The LED light unit, which is received in the hand-held casing, is used for illuminating the testing end portion of the conductive probe during testing. The LED light unit, which is also posi tioned away from the tip end of the probe casing, also acts to prevent heat, which is generated from the LED light unit, from being transmitted toward the conductive probe. The heat can affect an accuracy of measurement for the conductivity of the testing object.

Prior art document US 6043742 A discloses an apparatus for de tecting man-made gemstones using an alternating current con ducted through a sample gemstone. The apparatus includes a hand-held housing in which is disposed electronic circuitry, a probe which extends from the housing, and a transmitting stim ulus electrode in the form of a body-contact touchpad. The electronic circuitry includes a filter for eliminating non- transmitted signals sensed by the probe. In use, the operator probes the gemstone by touching the conductive probe to the gemstone in an attempt to sense signals conducted through the gemstone. The electronic circuitry is used for producing an alternating current signal, preferably in sine wave form, for delivery to the touchpad. The alternating current signal is transmitted through the operator of the apparatus into the sample gemstone. An alarm is activated upon the detection of the conducted transmitted signal, indicating that the gemstone is man-made. It is an objective of the application to provide an improved gemstone testing apparatus .

The application provides an improved light absorption gemstone testing apparatus for testing a gemstone specimen in order to identify the material of the specimen. Examples of the gem stone specimen are diamond and moissanite. The gemstone test apparatus serves as a light absorption test device.

A thermal conductivity test is often used to separate diamond and moissanite from all other gemstones. Thereafter, the light absorption gemstone testing apparatus can be used to differen tiate between diamond and moissanite.

The light absorption gemstone testing apparatus comprises a handheld casing, a plurality of light sources, a test probe, a photodetector, a processor unit, and a display unit.

The light sources, a part of the test probe, the photodetec tor, and the processor are often placed inside the handheld casing. The display unit are often placed on outer surface of the handheld casing.

The handheld casing acts to contain and protect inner parts of the light absorption gemstone testing apparatus . The shape of the handheld casing is designed for allowing a user to easily hold or carry the gemstone testing apparatus . The handheld casing can include grip indentations on an outer surface of the gemstone testing apparatus, thereby allowing the user to maintain a firm hold of the gemstone testing apparatus. The handheld casing is often made of plastic material to reduce weight and cost. A first end of the test probe is placed outside the handheld casing. A second end of the test probe is often placed inside the handheld casing. In other words, the test probe protrudes from one part of the handheld casing.

The plurality of light sources is place on at least two sides of the test probe. The multiple light sources are provided for emitting ultraviolet (UV) light rays with a predetermined wavelength. The light sources are inclined at a predetermined angle in order to direct the light rays towards an area that is in the vicinity of the first end of the test probe. UV light rays normally refer to an electromagnetic radiation with a wavelength from about 10 nm to about 400 nm, although the workable range can be narrower. The working range of the UV light rays can extend from about 300 nm to about 400 nm.

The specimen is intended to be placed at this area for receiv ing the light rays. If the specimen is a diamond, it would re flect the light rays. If the specimen is a moissanite, it would absorb the light rays. In other words, the moissanite would not reflect the light rays.

In use, the test probe is placed near to the specimen. The first end of the test probe is adapted for receiving light rays from the specimen, which is illuminated by light rays from the multiple light sources. The test probe then transmits these light rays to the second end of the test probe.

The test probe is often provided with a light guide, such as a tube with a reflective inner surface. One end of the test probe is intended to receive light rays. An inner surface of the test probe then reflects and directs the light rays to an other end of the test probe. The photodetector is often placed near to the second end of the test probe. The photodetector is arranged to detect light rays from the light sources with the predetermined wavelength. These light rays travelled from the specimen, to the first end, to the second end of the test probe, and to the photode tector. The photodetector is also arranged to measure a light intensity of these light rays.

The processor unit of an electronic testing unit is electri cally connected to the plurality of light sources and to the photodetector. The processor unit is provided for determining a material of the gemstone in accordance to a measurement of the light intensity of the light rays. In other words, the processor unit determines whether the specimen comprises a di amond or a moissanite.

If the processor unit determines that the specimen reflects light rays, then the processor unit considers the specimen is a diamond. On the other hand, if the processor unit determines that the specimen does not reflect light rays, then the pro cessor unit considers the specimen is a moissanite.

The display unit is electrically connected to the processor unit. The display unit is used for receiving a data regarding the determination of the material of the gemstone specimen from the processor unit. The display unit then shows or dis plays this data.

The plurality of light sources provides benefits.

The arrangement of the multiple light sources allows a table of the specimen to receive light rays while the test probe is placed at different parts of the table of the specimen, even at an edge of the table. The table refers to a facet or a flat side of a cut gemstone specimen, the facet being located at a top of the gemstone specimen. This facet is often the largest facet of the gemstone specimen.

In practice, the size of the test probe is often smaller than the size of the table of the specimen. A user may place the test probe at different parts of the table of the specimen.

When the test probe is placed substantially near or at the centre location of the table, the table of the specimen would receive light rays emitted from all multiple light sources.

When the test probe is not placed substantially near the cen tre location of the table of the specimen, such as at the edge of the table, the table of the specimen would still receive light rays emitted from one or more of the multiple light sources .

In short, the multiple light sources allow the specimen to re ceive sufficient light rays for testing the specimen, even when the test probe is placed at different parts of the table of the gemstone. The user is not restricted to place the test probe at the centre of the table in order to obtain an accu rate gemstone test result.

This is different from other gemstone tester with a test probe and with just one single light source being placed at one side of the test probe.

When the test probe is placed near or at a centre location of a table of a specimen, the table of the specimen would receive light rays from the single light source. When the test probe is placed at an edge of the table of the specimen, only a side facet of the specimen may receive light rays from the single light source. In other words, no light rays or little light rays are directed onto the table of the specimen .

The table of the specimen may then not receive enough light rays for testing the specimen. This then degrades or affects the testing to the specimen.

The light absorption gemstone testing apparatus can have dif ferent aspects .

In one implementation, the plurality of light sources of the light absorption gemstone testing apparatus comprises two light sources, although it can also comprise three or more light sources.

In a further implementation, the plurality of light sources is arranged around the test probe in a symmetric manner. In other words, the multiple light sources serve as similar parts that face each other or around a longitudinal axis of the test probe. In one example, two light sources are placed at two op posing sides of the test probe.

Each of the light sources is often inclined at a predetermined angle with respect to the longitudinal axis of the test probe.

The light absorption gemstone testing apparatus often includes a pressure switch and a pressure transmitting means.

In use, the test probe is brought in contact with a gemstone specimen and it is pressed against a table or a surface of the gemstone specimen. The table refers to a facet of the gemstone specimen. The pressing acts for transferring a force from the gemstone specimen to the test probe. The pressure transmitting means acts to transfer the force from the test probe to the pressure switch. Upon receiving the force from the pressure transmitting means, the pressure switch then transmits a sig nal to activate or power up the processor unit of the gemstone testing apparatus . The activated processor unit thereafter provides electrical power to the multiple light sources for illuminating the gemstone specimen for testing the specimen.

The pressure-switch together with the pressure transmitting means allows the multiple light sources to be powered up only when the gemstone testing apparatus is activated by the test probe pressing against the gemstone specimen.

This is different from other gemstone testers that are powered up when these gemstone testers are switched on. These gemstone testers can be powered up when their test probes are not pressing against a gemstone specimen.

This activating of the gemstone test apparatus by the pressing of the test probe serves to save power. This is because other gemstone testers can be powered up when their test probes are not pressing against a gemstone specimen. In other words, the other gemstone testers can be powered up when their test probes are both pressing and not pressing against a gemstone specimen. This feature is especially important when the gem stone testing apparatus is powered by a battery, which has a predetermined limit of energy storage capability.

Moreover, this activating of the gemstone test apparatus by the pressing of the test probe acts to prevent accidental ac tivation of testing of the gemstone specimen in that the gemstone testing is done when the test probe is not placed against the gemstone specimen.

As an example, the pressure transmitting means includes an ac tuator member that comprises a rod-like member. The rod-like member can also operate with a spring member. In use, when the actuator member is moved by the test probe, the actuator mem ber shifts towards the pressure switch, wherein the actuator member pushes an on/off button of the pressure switch for ac tivating the processor unit of the gemstone testing apparatus.

In one implementation, the pressure switch is provided in the form of a micro-switch. The micro-switch is normally in an open position. Upon receiving a force from the pressure trans mitting means, the micro-switch changes to a closed position. The micro-switch provides a switch position signal to the pro cessor unit for activating or powering up the processor unit in order to enable the gemstone testing apparatus to test the gemstone specimen.

In one aspect of the application, the multiple light sources of the light absorption gemstone testing apparatus emit light rays with a fixed wavelength that is between about 315 nm and about 400 nm while the photodetector is configured to detect light rays with this fixed wavelength. In other words, the photodetector with a peak detection sensitivity that is suita ble for detecting light rays with this fixed wavelength.

Alternatively, the light rays can also have different wave lengths that are between about 315 nm and about 400 nm. The photodetector is then configured to detect light rays with these different wavelengths. In one specific implementation, the multiple light sources emit light rays with a fixed wavelength of about 365 nm. The photodetector is configured to detect light rays with this fixed wavelength of about 365 nm.

In a different implementation, the plurality of light sources is replaced with a ring light. The ring light is arranged to surround the test probe. The ring light is used for emitting light rays from different sides of the test probe, wherein the light rays are directed towards the gemstone specimen.

The light absorption gemstone testing apparatus often includes an external cap that is intended for attaching to the handheld casing in order to cover and to protect the test probe from being damaged.

The external cap can further comprise a gemstone test refer ence tablet. The gemstone test reference tablet is capable of reflecting light rays from the multiple light sources. In use, a user uses the gemstone test reference tablet to check func tions of the gemstone testing apparatus.

The light absorption gemstone testing apparatus often includes a power source unit for supplying electrical power to parts of the gemstone testing apparatus, such as the multiple light sources, the photodetector, the electronic testing unit, and the display unit.

The light absorption gemstone testing apparatus can provide gemstone test results to the user in different ways.

In one implementation, the display unit of the light absorp tion gemstone testing apparatus includes a plurality of indi cator lights for providing visual indications of the gemstone test results. In other words, the display unit can include in dicator lights or a display screen for emitting light rays to visually display data regarding the gemstone test results.

In another implementation, the light absorption gemstone test ing apparatus further includes a buzzer or an audio speaker for generating an audio indication of the gemstone test re sult. An example of the audio indication includes a continuous or an intermittent beeping sound.

In another aspect of the application, the test probe includes a hollow light guide with a reflective inner surface. The re flective inner surface serves to reflect and direct light rays from one end to another end of the light guide.

In one specific implementation, the hollow light guide in cludes a metal tube.

The application also provides a method for differentiating be tween diamond and moissanite.

The method includes a step of a user pressing a test probe of the light absorption gemstone testing apparatus against a ta ble of a gemstone specimen. A force is then transmitted from the gemstone to the test probe and to a pressure switch of the gemstone testing apparatus .

After this, a plurality of light sources of the gemstone test ing apparatus is activated for illuminating the gemstone spec imen with light rays. The table of the gemstone specimen re ceives the light rays from at least one of the multiple light sources . If the gemstone specimen is a moissanite, the light rays are then absorbed. In other words, essentially no or little light rays are reflected from the moissanite. If the gemstone speci men is a diamond, the light rays are reflected to the test probe. An intensity of the light rays being reflected from the gemstone specimen is afterward measured. A material of the gemstone is later determined in accordance to the measured light intensity.

The method can include a further step of providing an indica tion of the material of the gemstone specimen to a user.

In one implementation, said step of providing the indication of the material of the gemstone specimen comprises a plurality of light indicators providing a visual indication of the de termined material of the gemstone specimen.

In another implementation, said step of providing the indica tion of the material of the gemstone specimen comprises a buzzer or speaker generating an audio indication of the deter mined material of the gemstone specimen.

The application also provides an improved combination gemstone testing apparatus for testing a gemstone specimen. The gem stone testing apparatus acts to determine which category of gemstone or jewel does the specimen falls under or belongs.

The gemstone testing apparatus includes a handheld casing, a processor unit, a first gemstone test device, a second gem stone test device, and a display unit.

The processor unit is enclosed in the handheld casing. A large part of the first gemstone test device and a large part of the second gemstone test device are also enclosed in the handheld casing. The display unit is placed on an outer surface of the handheld casing.

Referring to first gemstone test device, it includes a first test probe, a thermal conductivity test module, and an elec trical conductivity test module.

The first test probe is used for contacting a table of the gemstone specimen. The table refers to a facet or a flat side of the gemstone specimen. This facet is located at a top of the gemstone specimen and is often the largest facet of the gemstone specimen.

The thermal conductivity test module includes a heating ele ment and a temperature measurement unit.

In use, the heating element is electrically connected to the first test probe and to the processor unit for heating the first test probe for a predetermined period.

The temperature measurement unit is electrically connected to the first test probe for measuring a thermal conductivity of the specimen.

The processor unit is adapted to determine a first category of the specimen according to the thermal conductivity measure ment .

The first category refers to a category of simulants or to a category of a group consisting of diamond and moissanite. Ex amples of the simulant include cubic zirconia and sapphire or glass . A method performing a thermal conductivity test includes a step of a user pressing the first test probe against the table of the gemstone specimen.

The heating element then heats the first test probe for a pre determined period. The first test probe transmits heat energy to the gemstone specimen.

After this, the temperature measurement unit measures the thermal conductivity of the specimen by determining heat dis sipation of the first test probe, which provides an indication of heat dissipation of the gemstone specimen.

The processor unit then determines whether the gemstone speci men falls under the category of simulants or the category of a group consisting of diamond and moissanite according to the thermal conductivity measurement.

The electrical conductivity test module includes a first light source and an electrical conductivity test circuit.

In use, the first light source emits visible violet first light rays with a wavelength of about 425 nm to illuminate an area that is in the vicinity of an outer end of the first test probe .

The electrical conductivity test circuit is electrically con nected to the first test probe for measuring an electrical conductivity of the specimen.

The processor unit is adapted to determine a second category of the specimen according to the electrical conductivity meas urement . The second category refers to a category of possibly diamond or a category of moissanite.

A method of performing an electrical conductivity test in cludes a step of pressing the outer end of the first test probe against the table of the gemstone specimen.

The first light source then emits visible violet first light rays with a wavelength of about 425 nm, which travels the gem stone specimen for illuminating the gemstone specimen.

The electrical conductivity test circuit later measures an electrical conductivity of the specimen while the first light source is illuminating the gemstone specimen.

The processor unit then determines whether the specimen falls under the category of possibly diamond or the category of moissanite according to the electrical conductivity measure ment .

Referring to the second gemstone test device, it includes a second test probe and a light absorption module.

The second test probe is used for contacting the table of the specimen .

The light absorption module includes at least two second light sources and a photodetector.

In use, the second light sources are used for emitting ultra violet second light rays with a wavelength of about 365 nm to illuminate an area that is in the vicinity of an outer end of the second test probe. These two second light sources are pro vided adjacent to the second test probe. The second test probe includes a light guide for receiving the second light rays that are reflected from the specimen. The light guide is also used for transmitting the second light rays to an inner end of the second test probe. In other words, the second light rays travel from the outer end to the inner end of the second test probe.

The photodetector is provided at the inner end of the second test probe to measure a light intensity of the second light rays .

The processor unit is adapted to determine a third category of the specimen according to the light intensity measurement.

The third category refers to a category of diamond that is colourless or near colourless or to a category of moissanite.

The colourless diamond and the near colourless diamond are de fined according to the diamond colour chart, which is pub lished by the Gemmological Institute of America (GIA) .

A method of performing a light absorption test includes a step of pressing the second test probe against the table of the specimen .

The second light sources then emit ultra-violet second light rays with a wavelength of about 365 nm to illuminate the gem stone specimen.

The gemstone specimen can reflect the second light rays back to the second test probe, which acts to guide the second light rays to the inner end of the second test probe. The photodetector later measures a light intensity of the re flected second light rays.

The processor unit then determines whether the specimen falls under the category of diamond that is colourless or near col ourless and under the category of moissanite according to the light intensity measurement.

Referring the display unit, it is attached to the handheld casing for displaying the first category, the second category, and the third category of the gemstone specimen, which is de termined by the processor unit.

The combination gemstone testing apparatus allows a user to determine several categories a gemstone specimen with a single device. In practise, this is useful as the specimen can fall under different categories.

The combination gemstone testing apparatus provides the speci men category result with confidence without requiring the user to undergoing extensive training.

The gemstone testing apparatus also allows different test units, namely the thermal and the electrical conductivity test unit and the light absorption unit test, to share parts, such as the computing processor unit and the display unit. This al lows the gemstone testing apparatus to lower cost and ease of production .

Several implementations of the combination gemstone testing apparatus are possible. The first test probe often protrudes from a transparent hous ing portion, which is provided at one end portion of the handheld casing.

The first light source can emit light rays with a wavelength of between about 390 nm and about 450 nm.

In one implementation, the at least two second light sources refer to just two second light sources.

The second light sources can be arranged around the second test probe in a symmetric manner for ease of use.

The second light sources can emit light rays with a wavelength between about 315 nm and about 400 nm.

The second gemstone test device can include a pressure switch, and a pressure transmitting means for transferring a force from the second test probe to the pressure switch. The pres sure switch then transmits a switch status signal for activat ing the second gemstone test device.

The pressure switch can include or refer to a micro-switch.

The light guide can include or refer to a hollow metal tube.

The combination gemstone testing apparatus can include an ex ternal cap being attachable to the handheld casing for pro tecting the first test probe and the second test probe.

The external cap can include a gemstone test reference tablet that is provided for checking functions of the light absorp tion gemstone testing apparatus. The combination gemstone testing often includes a power source unit for supplying electrical power to the processor unit, the first gemstone test device gemstone testing apparatus, and the second gemstone test device gemstone testing apparatus .

The display unit can include a Liquid Crystal Display (LCD) display panel for displaying a category of the specimen, which is determined by the processor unit.

The combination gemstone testing apparatus can also include a buzzer for providing an audio indication of a category of the specimen, which is determined by the processor unit, to a user .

The subject matter of the application is described in greater detail in the accompanying Figures, in which

Fig . 1 illustrates a perspective view of an improved light absorption gemstone testing apparatus,

Fig . 2 illustrates a rear view of the light absorption gem stone testing apparatus of Fig. 1,

Fig . 3 illustrates a partial cross-sectional view of a head portion of the light absorption gemstone testing ap paratus of Fig. 1,

Fig . 4 illustrates an electronic block diagram of the light absorption gemstone testing apparatus of Fig. 1, Fig . 5 illustrates a partial cross-sectional view of the head portion of the light absorption gemstone test ing apparatus of Fig. 1, wherein a metal tube of the light absorption gemstone testing apparatus is placed at a centre portion of a table of a specimen,

Fig . 6 illustrates a partial cross-sectional view of the head portion of the light absorption gemstone testing apparatus of Fig. 1, wherein the metal tube is placed at an edge of the table of specimen,

Fig . 7 illustrates a partial cross-sectional view of a head portion of another gemstone tester with a single light source, wherein a test probe of the gemstone tester is placed at a centre portion of the table of the specimen,

Fig . 8 illustrates a partial cross-sectional view of the head portion of the light absorption gemstone test ing apparatus of Fig. 7, wherein the test probe is placed at an edge of the table of specimen,

Fig . 9 illustrates a top view of an external cap with a gemstone test reference tablet for the light absorp tion gemstone testing apparatus of Fig. 1,

Fig. 10 illustrates a flow chart of steps of a method of op erating the light absorption gemstone testing appa ratus of Fig. 1,

Fig. 11 illustrates a partial side view of the gemstone test reference tablet of Fig. 9,

Fig. 12 illustrates a further combination gemstone testing apparatus ,

Fig. 13 illustrates an electronic block diagram of the com bination gemstone testing apparatus of Fig. 12, Fig. 14 illustrates a metal detector circuit, an electrical conductivity test circuit, and a thermal conductiv ity test circuit of the block diagram of Fig. 13,

Fig. 15 illustrates a voltage generator module of Fig. 14, Fig. 16 illustrates a test probe of a thermal and electrical conductivity test device of the combination gemstone testing apparatus of Fig. 13, and

Fig. 17 illustrates a stone rest for a gemstone specimen. In the following description, details are provided to describe the embodiments of the specification. It shall be apparent to one skilled in the art, however, that the embodiments may be practiced without such details .

Some parts of the embodiments have similar parts. The similar parts may have the same names or similar part numbers with an alphabet symbol or prime symbol. The description of one part applies by reference to another similar part, where appropri ate, thereby reducing repetition of text without limiting the disclosure .

Figs. 1 to 3 show an improved light absorption gemstone test ing apparatus 10 to differentiate between diamond and mois- sanite. The gemstone testing apparatus 10 serves a light ab sorption test device.

In use, a gemstone specimen is often subjected to a thermal conductivity test. The thermal conductivity test is also called a heat conductivity test. If the thermal conductivity test indicates that the specimen can be a moissanite or a dia mond, the light absorption gemstone testing apparatus 10 is then used to determine whether the specimen is a moissanite or a diamond.

The light absorption gemstone testing apparatus 10 comprises an elongated handheld casing 13, a test probe 16 with a light module 19 together with a photodetector 21, a pressure-switch 25, an electronic testing unit 28, a display unit 30 together with a buzzer 92, and a power source unit 33. The electronic testing unit 28 is also called a testing electronic circuit. The photodetector 21 is also called an ultra-violet (UV) sen sor. The test probe 16 is also called a detector probe. The handheld casing 13 is also called an apparatus body. The power source unit 33 is also called a power source for the sake of brevity .

A part of the test probe 16, the light module 19, the photode tector 21, the pressure-switch 25, the electronic testing unit 28, a part of the power source unit 33, and the buzzer 92 are placed inside the elongated handheld casing 13. The display unit 30 is placed on an outer surface of the elongated handheld casing 13. The electronic testing unit 28 is electri cally connected to the power source unit 33, to the light mod ule 19, to the photodetector 21, to the pressure-switch 25, to the display unit 30, and to the buzzer 92. The electronic testing unit 28 is soldered on and is attached to a printed circuit board (PCB) .

The handheld casing 13 includes an elongated hollow body por tion 36, a head portion 38, and a spring support unit 40.

The elongated hollow body portion 36 essentially has a shape of a cylinder. The elongated hollow body portion 36 has a first end 36a and a second end 36b, which is positioned oppo site to the first end 36a. The head portion 38 is positioned next to the first end 36a of the elongated hollow body portion 36. A longitudinal axis of the elongated hollow body portion 36 is aligned with a longitudinal axis of the head portion 38. The spring support unit 40 is placed inside the elongated hol low body portion 36 and is attached to the head portion 38.

The head portion 38 includes a hollow conical member 42 with an actuator member 44 and a support member 47. The actuator member 44 is integrally connected to the hollow conical member 42. The hollow conical member 42 is placed next to the first end 36a of the hollow body portion 36 of the handheld casing 13. The actuator member 44 and the support member 47 are placed inside the first end 36a of the hollow body portion 36. The actuator member 44 is movably connected to the support member 47. The support member 47 is fixed to the hollow body portion 36 of the handheld casing 13.

The spring support unit 40 includes a plurality of coil tor sion springs 50. Parts of the actuator member 44 are inserted into the coil torsion springs 50. The coil torsion springs 50 are adapted for pushing the support member 47 away from the hollow conical member 42.

The pressure-switch 25 includes a mechanical micro-switch 52. The micro-switch 52 includes a rectangular body 55, an offset lever 57, and a single throw and single pole (STSP) switch 59, three electrical terminals 62. The STSP switch 59 includes an on/off button 65. One end of the offset lever 57 is movably attached to the rectangular body 55. A middle portion 57a of the offset lever 57 is placed next to the on/off button 65.

Two ends of the STSP switch 59 are electrically connected to two of the electrical terminals 62. The offset lever 57 is placed adjacent to one end of the actuator member 44. The electrical terminals 62 are electrically connected to the electronic testing unit 28.

The test probe 16 includes a metal tube 68 with a reflective inner surface 70 together with a protective shell 74. A first end 68a of the metal tube 68 protrudes from the head portion 38 and is placed outside the head portion 38. The protective shell 74 surrounds a second end 68b of the metal tube 68 and it touches the second end 68b of the metal tube 68. The pro tective shell 74 also provides a cavity 76 that is placed next to the second end 68b of the metal tube 68. As seen in Fig. 3, the light module 19 includes two light sources 78. The light sources 78 are positioned near to the test probe 16 and they are also placed around the test probe 16 in a symmetrical manner. The light sources 78 are placed opposite to each other. Each light source 78 includes a cylin drical body 78a and a semi-spherical part 78b that is placed at one end of the cylindrical body 78a. The cylindrical body 78a is inclined at an angle of about 40 degrees with respect to the longitudinal axis of the metal tube 68 and it is point ing towards a predetermined location that is positioned near to the first end 68a of the metal tube 68. The light sources 78 are electrically connected to the electronic testing unit 102 via current limiting resistors 96. Each light source 78 includes one ultraviolet (UV) Light Emitting Diode (LED) .

The photodetector 21 includes a photodiode 84. The photodiode 84 is placed adjacent to the second end 68b of the metal tube 68 and it is placed inside the cavity 76 that is formed by the protective shell 74. The photodiode 84 is also positioned along a longitudinal axis of the metal tube 68. The size of the photodiode 84 is comparable with the size of a diameter of the second end 68b of the metal tube 68.

The photodetector 21 has a peak detection sensitivity that corresponds with the wavelength of the ultraviolet light rays from the light sources 78. The photodetector 21 is also elec trically connected to the electronic testing unit 28.

The chamber, that is formed by the protective shell 74, acts to allow only the reflected light rays from the metal tube 68 to reach the photodetector 21 while prevent other light rays from reaching the photodetector 21. The display unit 30 comprises multiple indicator lights 89 to gether with a low battery indicator 108. The indicator lights 89 and the low battery indicator 108 are disposed on an outer surface of the hollow body portion 36 of the handheld casing 13. The display unit 30 is electrically connected to the elec tronic testing unit 28.

The buzzer 92 is placed inside the hollow body portion 36 of the handheld casing 13. The buzzer 92 is also electrically connected to the electronic testing unit 28.

As shown in Fig. 4, the electronic testing unit 28 includes a processor unit 102. The photodetector 21 and the light sources 78 together with the indicator lights 89, the low battery in dicator 108, and the buzzer 92 of the display unit 30 are electrically connected to the processor unit 102.

The power source unit 33 comprises a battery module 105 with a voltage regulator 107, a power socket connector 110, and a battery charger 112. The battery module 105, and the voltage regulator 107 are placed inside the hollow body portion 36.

The power socket connector 110 is partially enclosed in the hollow body portion 36 and is placed at the second end 36b of the hollow body portion 36. The battery charger 112 is adapted for electrically connecting to an external power source 114 and for electrically connecting to the power socket connector 110. The power socket connector 110 is electrically connected to the battery module 105. The battery module 105 and the voltage regulator 107 are adapted for providing electrical power to electronic components of the electronic testing unit 28. The battery module 105 includes a lithium battery that is electrically connected to contact terminals that are soldered onto the printed circuit board, which is attached to the elec tronic testing unit 28. In one implementation, the metal tube 68 has a length of about 9.30 millimetre (mm).

In a special implementation, the light source 78 produces a UV light ray with a wavelength of about 365 nm. The photodetector 21 has a peak detection sensitivity at about 365 nm.

The indicator lights 89 may be provided by LEDs with suitably chosen colours .

Functionally, the light absorption gemstone testing apparatus 10 provides a way to differentiate between colourless or near colourless diamond and moissanite.

The colourless diamond and the near colourless diamond are de fined according to the diamond colour chart, which is pub lished by the Gemmological Institute of America (GIA) .

In use, a thermal conductivity test can be used to separate diamond and moissanite from all other gemstones. Thereafter, the light absorption gemstone testing apparatus 10 can be used to differentiate between diamond and moissanite.

The light absorption gemstone testing apparatus 10 is intended to be held by a user such that the first end 68a of the metal tube 68 is placed on the surface of a specimen.

The user then presses the metal tube 68 against the specimen. The hollow conical member 42 with the actuator member 44 then moves into the body portion 36, along the longitudinal axis of the elongated body portion 36 by a substantially small dis tance. The hollow conical member 42 with the actuator member 44 also move towards the micro-switch 52. This movement acts to compress the springs 50.

The actuator member 44 afterward pushes the offset lever 57 of the micro-switch 52 such that the offset lever 57 pushes the on/off button 65 of the micro-switch 52 into the rectangular body 55 of the micro-switch 52.

The micro-switch 52 can be placed in a closed and a normally open position. The above pushing of the on/off button 65 acts to place the micro-switch 52, from the open position, to the closed position. The micro-switch 52 also acts to provide a switch position signal to the processor unit 102.

The current limiting resistor 96 acts to regulate electrical current to the light sources 78, when the light sources 78 are activated by the processor unit 102.

The activated light sources 78 produce ultraviolet light rays. The ultraviolet light rays are intended for illuminating a specimen, which is placed near to the test probe 16, when it is activated by the processor unit 102. The light ray is also called light for the sake of brevity.

The ultraviolet light rays have a predetermined fixed wave length that is within a predetermined UV light spectrum band. The ultraviolet light rays can also have different wavelengths that are within the predetermined UV light spectrum band. In one implementation, the predetermined UV light spectrum band is between about 315 nm and about 400 nm.

As seen in Figs. 5 and 6, the two light sources 78 allow a ta ble 120a of the specimen 120 to receive light rays from either one or two of the light sources 78, when the metal tube 68 is placed at different parts of the table 120a, such as an edge of the table 120a.

In practice, the size of the metal tube 68 is often smaller than the size of the table 120a of the specimen 120. Because of this, a user may place the metal tube 68 at different parts of the table 120a of the specimen 120. The metal tube 68 can be placed near to a centre location or be placed at an edge of the table.

The table 120a of the specimen 120 refers to a facet or a flat side of the gemstone specimen 120, the facet being located at a top of the specimen. One example of the specimen 120 is a diamond or moissanite. The flat facet is usually the largest facet of the specimen 120.

When the metal tube 68 is placed substantially near or at the centre location of the table 120a of the specimen 120, the ta ble 120a of the specimen 120 would receive light emitted from both light sources 78, as illustrated in Fig. 5.

When the metal tube 68 is not placed substantially near the centre location of the table 120a of the specimen 120, such as the edge of the specimen 120, the table 120a of the specimen 120 would still receive light emitted from one of the two light sources 78. This illustrated by ray lights with borders 78' in Fig. 6.

In short, the two light sources allow the table 120a of the specimen 120 to receive light rays from the light sources even when the metal tube 68 is placed at different parts of the ta ble 120a of the specimen 120. This is different from other gemstone tester with a test probe tube and with just one single light source.

When the test probe tube is placed near or at a centre loca tion of a table 120a of a specimen 120, the table 120a would receive light rays from the single light source, as shown in Fig. 7.

When the probe tube is placed at an edge of the table 120a of the specimen 120, only a side facet 120b of the specimen 120 may receive light rays from the single light source, as shown in Fig. 8. In other words, no light rays or little light rays are directed onto the table 120a of the specimen.

The specimen 120 may then not receive enough light rays for testing the specimen 120. This then degrade or affect the testing to the specimen 120.

Referring to the specimen 120, it can include a moissanite or a diamond. If the specimen 120 includes a moissanite, the moissanite would absorbs these light rays from the light sources 78. In other words, no light rays are reflected from the moissanite. If the specimen 120 includes a colourless or near colourless diamond, the diamond would reflect the light rays or reflect part of the light rays from the light sources 78.

The metal tube 68 acts as a light guide to receive the light rays reflected from the specimen 120. In detail, the second end 68b of the metal tube 68 receives the light rays reflected from the specimen 120. The inner surface of the metal tube 68 then reflects these light rays without absorbing these light rays. The inner surface also directs these light rays to the second end 68b of the metal tube 68 and towards the photode tector 21.

Referring to the protective shell 74, it provides a structural support for the two light sources 78 and for the metal tube 68, preventing them from moving.

The photodetector 21 detects and measures intensity of light rays being reflected from the specimen. The photodetector 21 then sends the light measurements to the processor unit 102.

The indicator lights 89 receives an electrical signal regard ing a gemstone test result from the processor unit 102 and then emits a corresponding light rays for showing the gemstone test result to a user. As an example, the indicator lights 89 activates a first LED for showing that the gemstone testing apparatus 10 detects a diamond. The indicator lights 89 acti vates a second LED for showing that the gemstone testing appa ratus 10 detects a moissanite.

The buzzer 92 also receives a signal from the processor unit 102 and generates a corresponding audio sound in accordance to the signal. The buzzer 92 produces a continuous beeping sound when the gemstone testing apparatus 10 detects a diamond. The buzzer 92 produces a short intermittent beeping sound when the gemstone testing apparatus 10 detects a moissanite.

After the indicator lights 89 emits a light ray for showing the gemstone test result to the user, the user can remove the metal tube 68 away from the specimen 120.

The coil torsion springs 50 then pushes the hollow conical member 42 and the actuator member 44 away from the micro switch 52. The actuator member 44 afterward does not push and does not contact the offset lever 57 of the micro-switch 52.

The micro-switch 52 then returns to its open position from its closed position. The micro-switch 52 then provides a switch position signal to the processor unit 102.

When the micro-switch 52 is placed in the closed position, the battery module 105 supplies electrical power to the light sources 78, to the electronic testing unit 28, and to the dis play unit 30.

The voltage regulator 107 allows the battery module 105 to provide an output voltage with a constant voltage level.

The battery charger 112 together with the power socket con nector 110 is used for connecting to an external power source 114. The connecting allows the external power source 114 to charge the battery module 105. The charging provides electri cal energy to the battery module 105.

The processor unit 102 includes a program or instructions to receive a switch position signal from the micro-switch 52. Af ter this, the processor unit 102 activates the light sources 78 according to the received switch position signal. The pro cessor unit 102 later also receives light intensity measure ments from the photodetector 21 after a predetermined period. The processor unit 102 then determines a gemstone test result in accordance to the light intensity measurements.

The processor unit 102 transmits an electrical signal regard ing the determined gemstone test result to the indicator lights 89. The processor unit 102 can also send a correspond ing signal to the buzzer 92.

The processor unit 102 monitors the output voltage of the bat tery module 105 and provides an alert signal to the low bat tery indicator 108. The low battery indicator 108 then emits a corresponding light ray to the user.

The handheld casing 13 acts to contain and protect parts of the gemstone testing apparatus, including the light module 19, the test probe 16, the power source unit 33 and the electronic testing unit 28 and the display unit 30.

The hollow conical member 42 of the head portion 38 is used for containing and protecting the light sources 78, the test probe 16, and the photodetector 21. The hollow conical member 42 also enclosed a part of the printed circuit board, which is attached to electronic testing unit 28.

The elongated hollow body portion 36 is provided for contain ing and protecting the pressure switch, the display unit 30, the power source unit 33 and a part of the electronic testing unit 28.

The light absorption gemstone testing apparatus 10 provides several benefits.

The two light sources 78 enable the table 120a of the specimen 120 to receive sufficient light rays from the light sources 78, even when the metal tube 68 is placed at different parts of the table 120a, such as an edge of the table 120a.

In use, the specimen 120 is often small. Because of this, a user may place the metal tube 68 at different parts of the table 120a of the specimen 120. For example, the metal tube 68 can be placed near to a centre location of the table 120a of the specimen 120. It can also be placed at an edge of the ta ble 120a. In spite of this, the two light sources 78 enable the specimen 120 to receive enough light rays for testing the specimen .

The length of the metal tube 68 prevents the metal tube 68 from being easily bent. A distance between the first end 68a of the metal tube 68 and the light sources 78 is also short enough to enable light rays from the light sources 78 to reach the specimen 120 with no or little loss of light rays, thereby not reducing light intensity.

In a general sense, the indicator lights 89 can be replaced by a display panel, such as a colour or a monochrome screen dis play, which can be provided by a Liquid Crystal Display (LCD) or an Organic Light-Emitting Diode (OLED) display.

The handheld casing 13 can comprise a catch which allows an external cap 121 to be attached to the handheld casing 13 us ing a snap-fit mechanism. The external cap 121 is used for protecting the test probe 16 from being damaged.

As shown in Figs. 9 and 11, the external cap 121 can include a fool-proof test disc 122. The test disc 122 is also called a gemstone test reference tablet. The term "fool-proof" implies that the test disc 122 is simple and easy to use such that a user does not or seldom uses the test disc 122 wrongly.

The test disc 122 is provided on an outer surface 121a of the external cap 121 for easy access. In particular, the outer surface 121a of the external cap 121 has a recessed area, wherein the test disc 122 is placed on the recessed area. The test disc 122 includes a layer 122a of transparent mate rial and a layer 122b of reflective material. An inner surface of the transparent material layer 122a is placed over and next to an outer surface of the reflective material layer 122b such that the transparent material layer 122a protects the reflec tive material layer 122b from being scratched or cut. An inner surface of the reflective material layer 122b is placed next to the recessed area of the external cap.

A user may use the test disc 122 to check functions of the gemstone testing apparatus 10. The user presses the first end 68a of the metal tube 68 of the test probe 16 of the gemstone testing apparatus 10 against the gemstone test reference tab let 122. The reflective material layer 122b then acts to re flect light rays from the light sources 78 of the gemstone testing apparatus 10, just like a diamond, while the transpar ent material layer 122a acts to protect the reflective mate rial layer 122b.

The metal tube 68 can be replaced by a light guide, such as a hollow tube, wherein an inner surface of the hollow tube is coated with a reflective layer.

The light absorption gemstone testing apparatus 10 can include three or more light sources, instead of just two light sources . These light sources are placed around the metal tube 68 in a symmetric manner. Each of the light sources can be po sitioned at a pre-determined angle with respect to the longi tudinal axis of the gemstone testing apparatus 10. The multi ple light sources can allow production of light rays with a higher intensity for illuminating the specimen 120. The light sources can be replaced by a ring light enclosing the test probe 16. The ring light can be configured to emit light rays that are directed to a location near the first end 68a of the metal tube 68. The ring light can also enable pro duction of light rays with a higher intensity for illuminating the specimen 120.

The processor unit 102 comprises a peripheral module that in cludes a timer. The timer can be programmed or instructed to switch off the electrical power of the gemstone testing appa ratus 10, when the electronic testing unit 28 is inactive for a predetermined period. Put differently, the gemstone testing apparatus 10 is automatically powered off when it is not in use for a predetermined period to conserve or save power.

The display unit 30 can include an electrical power indicator for showing that the electronic testing unit 28 is powered on.

Fig. 10 shows a flow chart 130 of a method of operating the light absorption gemstone testing apparatus 10.

The flow chart 130 includes a step 133 of a user providing a specimen 120.

The user then presses the metal tube 68 of the gemstone test ing apparatus 10 against the specimen, in a step 136. The metal tube 68 is placed such that it is about at right angle with respect to the table 120a of the specimen 120.

This later causes the micro-switch 52 to be placed, from its open position, to the closed position, in a step 140. The mi cro-switch 52 also provides a switch position signal to the processor unit 102. The processor unit 102 activates the multiple light sources and provides electrical current to the multiple light sources 78, in a step 143.

The activated multiple light sources 78 afterward produces ul traviolet light rays to illuminate the specimen 120, in a step 146.

The metal tube 68 subsequently directs these light rays to the second end 68b of the metal tube 68 and to the photodetector 21, in a step 149.

The photodetector 21 then measures intensity of light rays be ing reflected from the specimen 120, in a step 152.

The processor unit 102 then determines a gemstone test result in accordance to the light intensity measurements. The proces sor unit 102 transmits an electrical signal regarding the de termined gemstone test result to the indicator lights 89 and to the buzzer 92, in a step 155.

The indicator lights 89 receives the electrical signal regard ing a gemstone test result from the processor unit 102 and then emits a corresponding light ray for showing the gemstone test result to the user, in a step 160.

The buzzer 92 also receives the electrical signal from the processor unit 102 and then produces a corresponding audio sound according to the gemstone test result, in a step 163.

Fig. 12 shows another improved combination gemstone testing apparatus 210. The combination gemstone testing apparatus 210 includes an elongated handheld casing 213 with an electrical test circuit and a display unit 230. The handheld casing 213 encloses the electrical test circuit. The handheld casing 213 is also called an apparatus body. The display unit 230 is attached to an external part of the handheld casing 213.

As seen in Fig. 13, the electrical test circuit includes a test probe 330, a thermal and electrical conductivity test unit 212, a light absorption electrical test unit 211 and sup porting electronics. The handheld casing 213 surrounds and en closes the light absorption test unit 211, the thermal and electrical conductivity test unit 212, and the supporting electronics .

As seen in Fig. 12, the handheld casing 213 includes an elon gated hollow body portion and a head portion. The head portion is placed next to one end of the elongated hollow body por tion .

As seen in Fig. 13, the supporting electronics includes an electronic testing unit 228, a buzzer 292, and a power source unit 233. The electronic testing unit 228, the display unit 230, and the buzzer 292 are electrically connected to the power source unit 233. Moreover, the light absorption test unit 211 and the thermal and electrical conductivity test unit 212 are also electrically connected to the power source unit 233.

Referring to the thermal and electrical conductivity test unit 212, it includes a test probe 330, a conductivity test module, and a conductive housing finger pad 212d. The conductivity test module is electrically connected to the test probe 330 and to the housing finger pad 212d. The test probe 330 includes a copper rod or a thermocouple probe and a spring element 337. An outer end of the copper rod protrudes from the head portion of the handheld casing 213 while an inner end of the copper rod is placed in a hollow part of the head portion, as shown in Fig. 16. The inner end of the copper rod is connected to the spring element 337, as shown in Fig. 13.

The conductivity test module comprises a thermal conductivity test circuit module 212a, an electrical conductivity test cir cuit module 212b, and a metal detector circuit 212c. The elec trical conductivity test circuit module 212b and the metal de tector circuit 212c are electrically connected to an electri cal relay, which is electrically connected to the housing fin ger pad 212d.

The thermal conductivity test circuit module 212a includes a heater control and driver circuit 212a-l, and a thermocouple amplifier circuit 212a-2. The heater control and driver cir cuit 212a-l and the thermocouple amplifier circuit 212a-2 are electrically connected to the copper rod of the test probe 330 and to the electronic testing unit 228.

The electrical conductivity test circuit module 212b includes a visible violet light (VVL) light module 335. The VVL light module 335 is placed near the copper rod.

The VVL light module 335 includes a VVL Light Emitting Diode (LED) that generates light rays with a wavelength of about 425 nm. This VVL LED is provided inside a cylindrical reflector portion of the head portion of the handheld casing 213. The light ray is also light for the sake of brevity. The VVL LED generates or emits light rays with a wavelength of about 400 nm to about 430 nm with a peak light intensity of about 425 nm.

Fig. 14 shows electronic components of the thermal conductiv ity test circuit module 212a, electronic components of the electrical conductivity test circuit module 212b, and elec tronic components of the metal detector circuit 212c.

Fig. 15 shows electronic components of a high voltage genera tor module of the electrical conductivity test circuit module 212b.

Referring to the light absorption test unit 211, it includes a test probe tube 216, an ultraviolet (UV) light module 219, a photodetector 221, and a test electronic circuit, as seen in Fig. 13. The photodetector 221 is also called an ultra-violet (UV) sensor. The test probe tube 216 is also called a detector probe. The UV light module 219 and the photodetector 221 are electrically connected to the test electronic circuit. The UV light module 219 is placed near the test probe tube 216.

The test probe tube 216 includes a straight metal tube with a reflective inner surface and a probe pressure-switch 225. An outer end of the metal tube protrudes from the head portion of the handheld casing 213 while an inner end of the metal tube is placed in a hollow part of the head portion. Moreover, the pressure-switch 225 includes a mechanical micro-switch. Elec trical terminals of the micro-switch are electrically con nected to the electronic testing unit 228. The micro-switch is placed next to the inner end of the metal tube.

The UV light module 219 includes two light sources 219a and 219b. Each light source 219a and 219b includes one UV Light Emitting Diode (LED) . The light sources 219a and 219b are po sitioned near to the metal tube and they are also placed oppo site each other and are placed around the metal tube in a sym metrical manner.

The photodetector 221 refers to a photodiode. The photodiode is placed in the hollow part of the casing head portion such that the photodiode is placed adjacent to the inner end of the metal tube. The photodiode is also positioned along a longitu dinal axis of the metal tube. The photodiode is adapted to have a peak detection sensitivity that corresponds with a wavelength of light rays from the light sources 219a and 219b.

The light sources 219a and 219b produce an UV light ray with a wavelength of about 365 nm. The photodetector 221 has a peak detection sensitivity of about 365 nm.

In another implementation, the light sources 219a and 219b produce an UV light ray with a wavelength of between about 315 nm and about 400 nm.

The test electronic circuit also includes a reflectivity elec trical circuit 211a and an LED driver 211b. The LED driver 211b is electrically connected to the light sources 219a and 219b and to the electronic testing unit 228. The reflectivity electrical circuit 211a is electrically connected to the pho todiode of the photodetector 221 and to the electronic testing unit 228.

Referring to the electronic testing unit 228, it includes a computing processor unit or a microcontroller. Referring to the display unit 230, it comprises a Liquid Crys tal Display (LCD) display panel. The display unit 230 is elec trically connected to the electronic testing unit 228.

Referring to the buzzer 292, it is placed inside the handheld casing 213. The buzzer 292 is electrically connected to the electronic testing unit 228.

Referring to the power source unit 233, it comprises a power socket connector 310, a battery charger 312, and a battery module 305 with a voltage regulator 307. The battery module 305 includes a lithium battery. The battery charger 312, the battery module 305, and the voltage regulator 307 are placed inside the hollow body portion of the handheld casing 213. The power socket connector 310 is placed at the one end of the hollow body portion.

The power socket connector 310 is electrically connected to the battery charger 312. The battery charger 312 is electri cally connected to the battery module 305.

The voltage regulator 307 is electrically connected to the UV light module 219, to the photodetector 221, and to the light absorption test unit 211. Furthermore, the voltage regulator 307 is electrically connected to the VVL light module 335 and to the thermal and electrical conductivity test unit 212.

Moreover, the voltage regulator 307 is electrically connected to the electronic testing unit 228, which is electrically con nected to the display unit 230, and to the buzzer 292.

Further, the handheld casing 213 can comprise a catch for al lowing the handheld casing 213 to attach to an external cap 421 using a snap-fit mechanism. The external cap 421 can be attached to and can be detached from the handheld casing 213. The external cap 421 is used for protecting the test probe tube 216 and the test probe 330 from being damaged.

The external cap 421 can include a fool-proof test disc 422. The test disc 422 is also called a gemstone test reference tablet .

The test disc 422 is provided on an outer surface of the ex ternal cap 421 for easy access. In particular, the outer sur face of the external cap 421 has a recessed area, wherein the test disc 422 is placed on the recessed area.

The test disc 422 includes a layer of transparent material and a layer of reflective material. An inner surface of the trans parent material layer is placed over and next to an outer sur face of the reflective material layer such that the transpar ent material layer protects the reflective material layer from being scratched or cut. An inner surface of the reflective ma terial layer is placed next to the recessed area of the exter nal cap 421.

A user may use the test disc 422 to check functions of the combination gemstone testing apparatus 210. The user presses one end of the metal tube of the test probe 216 of the gem stone testing apparatus 210 against the gemstone test refer ence tablet 422. The reflective material layer then acts to reflect light rays from the light sources 219a and 219b of the UV light module 219 of the gemstone testing apparatus 210, just like a diamond, while the transparent material layer acts to protect the reflective material layer.

Functionally, the thermal conductivity test circuit module 212a provides a way to separate simulant, such as cubic zirconia and sapphire or glass from a group consisting of dia mond and moissanite.

A thermal conductivity test is described below.

The thermal conductivity test includes a step of a user hold ing and positioning a gemstone specimen 320 near or next to the gemstone test apparatus 210.

The user may place the gemstone specimen 320 on a stone rest or holder and then the user holds the stone rest.

Fig. 17 shows a stone rest 340 for the gemstone specimen 320. The stone rest 340 comprises recessed areas 342 that are con figured for receiving different gemstones with different di mensions. The recessed areas 342 positions and holds the gem stone specimen 320 such that the gemstone specimen 320 is sta ble for testing.

Alternatively, the user may also mount the gemstone specimen 320 on a ring and then the user hold or wear the ring on his finger, wherein the user positions and holds the gemstone specimen 320 such that the gemstone specimen 320 is stable for testing .

The test probe 330 is then placed on a table or a major top surface of the specimen 320.

The spring element 337 enables the test probe 330 to provide an approximately consistent pressure on the gemstone specimen 320. The spring element 337 also acts to prevent the test probe 330 from being bent. The placing of the test probe 330 onto the specimen 320 also acts to press the test probe 330 against the specimen 320. The spring element 337 then allows the test probe 330 to move slightly inwards. This inward movement serves to prevent the test probe 330 from being bent during this pressing. After this, when the test probe 330 is not pressed against the spec imen 320, the spring element 337 acts to move the test probe 330 to its initial position.

The metal detector circuit 212c automatically detects when the test probe 330 has accidentally touched a metal surface and provides a corresponding acoustic and/or optic alert signal to indicate this touching.

After this, the heater control and driver circuit 212a-l heats the test probe 330, which is placed on the table of the speci men 320, for a predetermined period such that the heated test probe 330 transmits heat to the table of the specimen 320.

The thermocouple amplifier circuit 212a-2 later measures tem perature or heat dissipation rate of the test probe 330 and sends the respective measurement to the processor unit of the electronic testing unit 228.

Moissanite and diamond have comparable thermal conductivities . In comparison, simulant, such as cubic zirconia and sapphire, can be distinguished from a group consisting of diamond and moissanite by comparing their thermal conductivity properties .

The processor unit afterward determines or selects a category of the specimen 320 according to the heat dissipation measure- ments . If the processor unit determines that the specimen 320 falls under the category of simulant, the processor unit then sends a signal to the display unit 230 for showing or indicating the category, which is selected by the processor unit, to a user.

On the other hand, if the processor unit determines that the specimen 320 falls under the category of the group consisting of diamond and moissanite, the processor unit then proceeds to perform an electrical conductivity test.

Functionally, the electrical conductivity test circuit module 212b provides a way to differentiate between colourless or near colourless diamonds and most moissanites.

An electrical conductivity test is described below.

The electrical conductivity test includes a step of a user holding and positioning a gemstone specimen 320 near or next to the gemstone test apparatus 210.

The test probe 330 is then placed on a table or a major top surface of the specimen 320.

Following this, the VVL light module 335 illuminates the gem stone specimen 320 with visible violet light rays with a wave length of about 425 nm while the test probe 330 is still in contact with the gemstone specimen 320. The VVL light module 335 and the head portion of the handheld casing 213 are ar ranged to allow light rays from the VVL light module 335 to reach the gemstone specimen 320 when test probe 330 is in con tact with the gemstone specimen 320. While the specimen 320 is being illuminated with these visible violet light rays or shortly after the specimen 320 is illumi nated with these visible violet light rays, the electrical conductivity test circuit module 212b receives an electrical voltage signal from the test probe 330 that receives the elec trical voltage signal from the surface of the specimen 320.

An electrical current later flow from the electrical conduc tivity test circuit module 212b, to the conductive housing finger pad 212d, to a finger of a user that is pressing the housing finger pad, to a human body of the user, to another finger of the user, to either a stone rest that is supporting the gemstone specimen 320 or to a ring on which the gemstone specimen 320 is mounted, to the gemstone specimen 320, to the test probe 330, and back to the electrical conductivity test circuit module 212b.

The electrical conductivity test circuit module 212b then measures this electrical current, which relates to an electri cal conductivity of the specimen 320.

After this, the electrical conductivity test circuit module 212b sends this electrical current measurement to the proces sor unit.

The processor unit later determines whether the specimen 320 falls in a category of possibly diamond or a category of mois- sanite, according to the electrical current measurement.

Most moissanites are electrically conductive while FI mois- sanites have high electrical resistance. On the other hand, most diamonds, which are colourless or near colourless, are not electrically conductive while some lab-grown synthetic di amonds are electrically conductive. After this, the processor unit sends a signal to the display unit 230 for showing or indicating the category of the speci men 320, which is determined by the processor, to a user.

Functionally, the light absorption test unit 211 provides a way to differentiate between colourless or near colourless di amond and moissanite.

A light absorption test is described below.

The light absorption test includes a step of a user holding and positioning a gemstone specimen 320.

A user then holds the handheld casing 213 such that an outer end of the metal tube of the test probe tube 216 is placed on a table or a major flat surface of the gemstone specimen 320. The user then presses the metal tube against the table of the specimen 320.

A spring 250 later acts to bring the metal tube to its initial position when the user stops the pressing of the metal tube against the specimen 320.

The micro-switch of the pressure-switch 225 can be placed in a closed and a normally open position. The above pressing or pushing of the metal tube against the specimen 320 acts to change a position of the micro-switch. The micro-switch can be changed from the open position to the closed position or from the closed position to the open position. The micro-switch also acts to provide a switch position status signal to the processor unit of the electronic testing unit 228. The processor unit includes a program or instructions to re ceive the switch position status signal from the micro-switch.

The light sources 219a and 219b of the UV light module 219 are then activated by the processor unit according to the switch position signal. The activated light sources 219a and 219b later produce ultraviolet light rays with a wavelength of about 365 nm for illuminating the above-mentioned gemstone specimen 320.

The UV light module 219 and the head portion of the handheld casing 213 are arranged to allow light rays from the light sources 219a and 219b to reach a gemstone specimen, which is placed near to the outer end of the metal tube of the test probe tube 216.

The arrangement of these two light sources 219a and 219b allow the table of the specimen 320 to receive light rays from ei ther one light sources 219a and 219b or from both light sources 219a and 219b, when the metal tube is placed at dif ferent parts of the specimen table.

In practice, the size of the metal tube is often smaller than the size of the specimen table. Because of this, a user may place the metal tube at different parts of the specimen table. The metal tube can be placed near to a centre location or be placed near to an edge of the specimen table.

When the metal tube is placed substantially near or at the centre location of the specimen table, the specimen table would receive light rays emitted from both light sources 219a and 219b. When the metal tube is placed substantially near the edge of the specimen 320, the specimen table can still receive light emitted from one of the two light sources 219a and 219b.

In effect, the two light sources 219a and 219b allow the spec imen table to receive light rays from at least one of the light sources 219a and 219b even when the metal tube is placed at different parts of the specimen table.

This is different from other gemstone tester with a test probe tube and with just one single light source, wherein a specimen may then not receive enough light rays for testing the speci men, which can degrade or affect the testing to the specimen, when the test probe is not placed at a centre portion of the table .

Referring to the specimen 320, it can refer to a moissanite or to a diamond. The moissanite would absorbs these light rays from the light sources 219a and 219b. In other words, essen tially no light rays are reflected from the moissanite. On the other hand, a colourless or near colourless diamond would re flect all or most of the light rays from the light sources 219a and 219b.

The metal tube of the test probe tube 216 acts as a light guide to receive the light rays reflected from the specimen 320.

The photodiode of the photodetector 221 later detects and measures intensity of these light rays from the metal tube.

The photodetector 221 then sends the light measurements to the processor unit. The photodiode is intended for receiving light rays from the metal tube and not for receiving light rays from other sources. The processor unit later selects or determines whether the gemstone specimen 320 falls in the category of diamond, the diamond being colourless or near colourless, or in the cate gory of moissanite in accordance to the light measurements. After this, the processor unit generates a corresponding gem stone category signal and sends the gemstone category signal to the display unit 230.

The display unit 230 later shows and indicates the category selected by the processor unit to the user.

The buzzer 292 also is intended for receiving a signal from the processor unit and generating a corresponding audio sound to alert the user.

The power socket connector 310 is intended for receiving elec trical power from an external power source 314 and for trans ferring this electrical power to the battery charger 312.

The battery charger 312 then converts a voltage of the elec trical power to another voltage that is suitable for the bat tery module 305. The battery charger 312 later transfers this converted electrical power to the battery module 305.

The battery module 305 stores this electrical power and after ward supplies the stored electrical power to the voltage regu lator 307.

The voltage regulator 307 then provides electrical power with a voltage that falls within a predetermined regulated range to the UV light module 219 and to the photodetector 221, which are both activated and controlled by the light absorption test unit 211. The voltage regulator 307 also supplies this electrical power to the VVL light module 335, which is activated and controlled by the heater control and driver circuit 212a-l, the electri cal conductivity test circuit module 212b, and the metal de tector circuit 212c.

The voltage regulator 307 also supplies this electrical power to the processor unit of the electronic testing unit 228, which controls the display unit 230, and the buzzer 292.

The gemstone testing apparatus provides several benefits .

The gemstone testing apparatus enables the user to obtain pa rameters of a gemstone specimen with a single gemstone test unit. This is useful as the different parameters allow cate gory of the specimen to be determined with greater accuracy.

In other words, the material of the specimen can be determined with higher confidence.

The gemstone testing apparatus also allows different test units, namely the thermal and the electrical conductivity test unit and the light absorption unit test, to share parts, such as computing processor unit and display unit. In other words, the thermal and the electrical conductivity test unit and the light absorption unit test produced separately would require more parts and hence are more complex and cost more.

In short, the embodiment provides a tester that is provided or designed to distinguish colourless or near colourless faceted diamond from moissanite.

Regarding thermal conductivity, most diamonds are extremely efficient thermal conductors. Diamonds conduct heat well because they have carbon atoms that are linked strong covalent bonds, these carbon atoms are part of a diamond crystal. For instance, thermal conductivity of natural diamond is around 22 W/ (cm-K), which makes the natural diamond five times better at conducting heat than copper.

Moissanite is a crystalline form of silicon carbide that re sembles diamond. Moissanite and diamond have comparable ther mal conductivities.

Simulant, such as cubic zirconia and sapphire, can be distin guished from a group consisting of diamond and moissanite by comparing their thermal conductivity properties .

Regarding electrical conductivity, most diamonds, which are colourless or near colourless, are not electrically conduc tive. Some lab-grown synthetic diamonds are electrically con ductive. The synthetic diamonds are produced using some impu rities which cause these synthetic diamonds to become electri cally conductive.

Most moissanites are electrically conductive. Moreover, elec trical resistance of FI moissanite is higher than normal mois sanite. In addition, the electrical resistance varies on dif ferent surface areas of the FI Moissanite.

Colourless or near colourless diamonds can be distinguished from most moissanites by comparing their electrical conductiv ity.

Regarding light absorption test, colourless or near colourless diamonds can be distinguished from moissanites by comparing their light absorption or reflection properties . This tester has a pen-like shape with two probes being pro vided at one end of the tester.

One probe is intended to perform a thermal conductivity test and an electrical conductivity test, the electrical conductiv ity test being performed together with a visible violet light rays with a wavelength of about 425 nm.

Another probe is intended to perform light absorption test with an ultraviolet LED light ray with a wavelength of about 365 nm.

The thermal conductivity test and the electrical conductivity test can separate simulant from a group consisting of diamond and moissanite and can separate colourless or near colourless diamonds from most moissanites. On the other hand, the light absorption test can separate moissanites from colourless or near colourless diamonds.

The embodiments can also be described with the following lists of features or elements being organized into an item list. The respective combinations of features, which are disclosed in the item list, are regarded as independent subject matter, re spectively, that can also be combined with other features of the application.

A feature list for a thermal and electrical conductivity gem stone testing apparatus is shown below.

1. A thermal and electrical conductivity gemstone testing apparatus comprising

an apparatus body, the apparatus body enclosing electronic circuitry, a visible violet light (VVL) emitter for generating visible violet light rays,

a reflector housing,

a transparent housing portion, the transparent hous ing portion being transparent for visible violet light rays, the transparent housing portion being provided adjacent to the reflector housing,

a detector probe (or tube), the detector probe pro truding from the transparent housing portion, wherein the visible violet light emitter is provided within the reflector housing and the reflector housing is provided for directing the visible violet light of the visible violet light emitter through the transparent housing portion into the vicinity of a tip of the detec tor probe, and

wherein the detector probe and the visible violet light emitter are connected to the electronic circuitry, the electronic circuitry comprising a thermal and electrical conductivity sensing circuitry that is connected to the detector probe and to a processing unit, the processing unit being operative to turn on the visible violet light emitter and to perform a subsequent conductivity measure ment using the thermal and electrical conductivity sens ing circuitry. The thermal and electrical conductivity gemstone testing apparatus of item 1, wherein

the visible violet light emitter capable of emitting light rays with a wavelength of about 400 nm to about 430 nm. The thermal and electrical conductivity gemstone testing apparatus of one of the items 1 to 2, wherein the detector probe is provided at an end portion of the transparent housing portion.

4. The thermal and electrical conductivity gemstone testing apparatus according to one of the items 1 to 3, wherein a back surface of a chamber that is defined between the transparent housing portion.

5. The thermal and electrical conductivity gemstone testing apparatus according to one of the preceding items, wherein the reflective layer is provided by electroplat ing .

6. The thermal and electrical conductivity gemstone testing apparatus according to one of the preceding items, the gemstone testing apparatus comprising a display region that is connected to the processing unit.

7. The thermal and electrical conductivity gemstone testing apparatus according to item 6, wherein

the display region comprises indicator LEDs.

8. The thermal and electrical conductivity gemstone testing apparatus according to one of the preceding items, wherein

the transparent housing portion is conically tapered from the reflector housing towards a tip end of the transpar ent housing portion.

9. The thermal and electrical conductivity gemstone testing apparatus according to one of the preceding items further comprising a power source unit for supplying electrical power to the thermal and electrical conductivity gemstone testing ap paratus .

10. The thermal and electrical conductivity gemstone testing apparatus according to one of the preceding items further comprising

a buzzer for providing an audio indication of a gemstone test result.

11. A head portion for a thermal and electrical conductivity gemstone testing apparatus, the head portion comprising a reflector housing,

a transparent housing portion, the transparent hous ing portion being attached to the reflector housing, the transparent housing portion being transparent for visible violet light rays, and

a detector probe (or tube), the detector probe pro truding from the transparent housing portion, the detector probe having connections for connecting to electronic circuitry of the gemstone testing appa ratus .

12. The head portion of item 11, comprising

a visible violet light emitter being provided within the reflector housing, and the visible violet light emitter having connections for connecting to the electronic cir cuitry.

13. A method for producing a thermal and electrical conduc tivity gemstone testing apparatus, the method comprising providing a transparent housing portion with a de tector probe, attaching the transparent housing portion to the re flector housing,

providing an apparatus body,

connecting a visible violet light emitter to elec tronic circuitry of the apparatus body,

connecting the detector probe to the electronic cir cuitry,

attaching the reflector housing to the apparatus body .

A feature list for a light absorption gemstone testing appa ratus is shown below.

1. A light absorption gemstone testing apparatus for testing a gemstone specimen, the gemstone testing apparatus com prising

a handheld casing,

a plurality of light sources,

a test probe being placed at one end of the handheld casing,

a first end of the test probe is placed outside the handheld casing, the plurality of light sources is pro vided for emitting light rays towards an area that is in the vicinity of the first end, and the first end is adapted for receiving light rays from the specimen and for transmitting the light rays to a second end of the test probe,

a photodetector, the photodetector being arranged to measure an intensity of the light rays from the second end,

a processor unit for determining a material of the specimen in accordance to a measurement of the intensity of the light rays, and a display unit for displaying a gemstone test re sult , wherein

the plurality of light sources is provided on at least two sides of the test probe. The light absorption gemstone testing apparatus according to item 1, wherein

the plurality of light sources comprises two light sources . The light absorption gemstone testing apparatus according to item 1 or 2 , wherein

the plurality of light sources is arranged around the test probe in a symmetric manner. The light absorption gemstone testing apparatus according to one of the preceding items, wherein

the plurality of light sources emits light rays with a wavelength between about 315 nm and about 400 nm. The light absorption gemstone testing apparatus according to item 4, wherein

the plurality of light sources emits light rays with a wavelength of about 365 nm. The light absorption gemstone testing apparatus according to one of the preceding items further comprising

an external cap being attachable to the handheld casing for protecting the test probe. The light absorption gemstone testing apparatus according to item 6, wherein the external cap comprises a gemstone test reference tab let that is provided for checking functions of the light absorption gemstone testing apparatus .

8. The light absorption gemstone testing apparatus according to one of the preceding items further comprising

a power source unit for supplying electrical power to the light absorption gemstone testing apparatus

9. The light absorption gemstone testing apparatus according to one of the preceding items, wherein

the display unit comprises a plurality of indicator lights for providing visual indications of the gemstone test result.

10. The light absorption gemstone testing apparatus according to one of the preceding items further comprising

a buzzer for providing an audio indication of the gem stone test result.

11. The light absorption gemstone testing apparatus according to one of the preceding items, wherein

the test probe comprises a hollow light guide with a re flective inner surface.

12. The light absorption gemstone testing apparatus according to item 11, wherein

the light guide comprises a metal tube.

13. A method for differentiating between a diamond and a

moissanite, the method comprising

pressing a (metal tube of a) test probe of a gem stone testing apparatus against a gemstone specimen, transmitting a force from the test probe to a pres sure switch of the gemstone testing apparatus, activating a plurality of light sources of the gem stone testing apparatus for illuminating the gem stone specimen,

wherein the gemstone specimen receives light rays from at least one light source,

measuring an intensity of the light rays being re flected from the gemstone specimen, and

determining a material of the gemstone specimen in accordance to the measured light intensity.

14. The method according to item 13 further comprising

providing an indication of the material of the gemstone specimen to a user.

15. The method according to item 14, wherein

the provision of the indication of the material of the gemstone specimen comprises providing a visual indication of the material of the gemstone specimen.

19. The method according to item 13 or 14, wherein

the provision of the indication of the material of the gemstone specimen comprises providing an audio indication of the material of the gemstone specimen.

A feature list for a combination gemstone testing apparatus is shown below.

1. A combination gemstone testing apparatus for testing a gemstone specimen, the gemstone testing apparatus com prising

a handheld casing, a processor unit being enclosed in the handheld cas ing,

a first gemstone test device comprising

a first test probe for contacting a table of the gemstone specimen,

a thermal conductivity test module comprising a heating element being electrically con nected to the first test probe for heating the first test probe for a predetermined period, a temperature measurement unit being elec trically connected to the first test probe for measuring a thermal conductivity of the speci men,

wherein the processor unit is adapted to deter mine a first category of the specimen according to the thermal conductivity measurement, an electrical conductivity test module compris ing

a first light source for emitting first light rays with a wavelength of about 425 nm to illuminate an area that is in the vicinity of an outer end of the first test probe, and

an electrical conductivity test circuit being electrically connected to the first test probe for measuring an electrical conductivity of the specimen,

wherein the processor unit is adapted to deter mine a second category of the specimen accord ing to the electrical conductivity measurement, a second gemstone test device comprising

a second test probe for contacting the table of the specimen,

a light absorption module comprising at least two second light sources for emitting second light rays with a wavelength of about 365 nm to illuminate an area that is in the vicinity of an outer end of the second test probe, the at least two second light sources being provided adjacent to the second test probe, the second test probe comprises a light guide for receiving the second light rays that are reflected from the specimen and for trans mitting the second light rays to an inner end of the second test probe, and

a photodetector being provided at the in ner end of the second test probe to measure a light intensity of the second light rays, wherein the processor unit is adapted to deter mine a third category of the specimen according to the light intensity measurement, and a display unit being attached to the handheld casing for displaying a category of the specimen, which is de termined by the processor unit. The combination gemstone testing apparatus according to item 1,

wherein the first test probe protrudes from a transparent housing portion, which is provided at one end portion of the handheld casing. The combination gemstone testing apparatus according to item 1 or 2, wherein

wherein the first light source emits light rays with a wavelength of between about 390 nm and about 450 nm. The combination gemstone testing apparatus according to one of the above-mentioned items, wherein the at least two second light sources comprises two sec ond light sources.

The combination gemstone testing apparatus according to one of the above-mentioned items, wherein

the at least two second light sources are arranged around the second test probe in a symmetric manner. The combination gemstone testing apparatus according to one of the above-mentioned items, wherein

the plurality of second light sources emit light rays with a wavelength between about 315 nm and about 400 nm. The combination gemstone testing apparatus according to one of the above-mentioned items, wherein

the second gemstone test device comprises

a pressure switch, and

a pressure transmitting means for transferring a force from the second test probe to the pressure switch, wherein the pressure switch transmits a switch status signal for activating the second gemstone test device. The combination gemstone testing apparatus according to item 7, wherein

the pressure switch comprises a micro-switch. The combination gemstone testing apparatus according to item 1, wherein

the light guide comprises a hollow metal tube.

The combination gemstone testing apparatus according to one of the above-mentioned items further comprising an external cap being attachable to the handheld casing for protecting the first test probe and the second test probe .

11. The combination gemstone testing apparatus according to item 10, wherein

the external cap comprises a gemstone test reference tab let that is provided for checking functions of the light absorption gemstone testing apparatus .

12. The combination gemstone testing apparatus according to one of the above-mentioned items further comprising a power source unit for supplying electrical power to the processor unit, the first gemstone test device gemstone testing apparatus, and the second gemstone test device gemstone testing apparatus.

13. The combination gemstone testing apparatus according to one of the above-mentioned items, wherein

the display unit comprises a Liquid Crystal Display (LCD) display panel for displaying a category of the specimen, which is determined by the processor unit.

14. The combination gemstone testing apparatus according to one of the above-mentioned items further comprising a buzzer for providing an audio indication of a category of the specimen, which is determined by the processor unit, to a user.

Although the above description contains much specificity, these should not be construed as limiting the scope of the em bodiments but merely providing illustration of the foreseeable embodiments. Especially the above stated advantages of the em bodiments should not be construed as limiting the scope of the embodiments but merely to explain possible achievements if the described embodiments are put into practise. Thus, the scope of the embodiments should be determined by the claims and their equivalents, rather than by the examples given.

REFERENCE NUMBERS

10 light absorption gemstone testing apparatus

13 elongated handheld casing

16 test probe

19 light module

21 photodetector

25 pressure switch

28 electronic testing unit

30 display unit

33 power source unit

36 elongated hollow body portion

36a first end of the elongated hollow body portion

36b second end of the elongated hollow body portion

38 head portion

40 spring support unit

42 hollow conical member of the head portion

44 actuator member of the head portion

47 support member

50 coil torsion springs

52 mechanical micro-switch

55 rectangular body

57 offset lever

59 single throw and single pole (STSP) switch

62 electrical terminals

65 on/off button

68 metal tube

68a first end of the metal tube

68b second end of the metal tube

70 reflective inner surface

74 protective shell

76 cavity formed by the protective shell

78 light sources

78' border of light rays

84 photodiode 89 indicator lights

92 buzzer

96 current limiting resistors

102 processor unit

105 battery module

107 voltage regulator

108 low battery indicator

110 power socket connector

112 battery charger

114 external power source

120 specimen

120a table of the specimen

120b side facet of the specimen

121 external cap

121a outer surface

122 fool-proof test disc

122a layer

122b layer

130 flow chart

133 step

136 step

140 step

143 step

146 step

149 step

152 step

155 step

160 step

163 step

210 combination gemstone testing apparatus

211 light absorption test unit

211a reflectivity electrical circuit

211b LED driver

212 thermal and electrical conductivity test unit 212a thermal conductivity test circuit module

212a-l heater control and driver circuit

212a-2 thermocouple amplifier circuit

212b electrical conductivity test circuit module 212c metal detector circuit

212d conductive housing finger pad

213 handheld casing

216 test probe tube

219 UV light module

221 photodetector

225 probe pressure-switch

228 electronic testing unit

230 display unit

233 power source unit

250 spring

292 buzzer

310 power socket connector

312 battery charger

305 battery module

307 voltage regulator

314 external power source

320 specimen

330 test probe

335 VVL light module

337 spring element

340 stone rest

342 recessed area