PURPOSE: To obtain a preservative which can be widely used for purification and prevention of rotting of drinking water and preservation of various processed or pherishable foods by mixing glauconite with sodium chloride.

CONSTITUTION: A preservative containing as active ingredients glauconite and sodium chloride in an amount of 5-10wt.% based thereon. Glauconite is a multi- element mineral comprising a specific metamorphite wherein chlorite, hornblende, apatite, etc., congregate, mainly comprises silicic acid, and contains potassium, sodium, calcium, alumina, and various transition metal elements such as iron, nickel, chromium, cobalt, vanadium, etc. Sodium chloride is an essential mineral for the human body, has a sterile effect which inhibits proliferation of bacteria, and has long been used not only as a seasoning but also as a food preservative. When this preservative is used for drinking water, it prevents the water from rotting, thus not only making the water storable for a long period of time but also converting the water into a weakly alkaline good mineral water, and it keeps foods such as perishable vegetables, fishes, shell-fishes, etc., fresh for a long period of time.