Marble is metamorphic, calcium carbonate of ultrafine, crystalline structure. It is used as building and ornamental stone (chips), artifical stone, source of carbon dioxide, neutralization of acids. The optimum yeild of calcium carbonate (precipitated) from marble chips is 50%. Precipitated calcium carbonate is used in dentificers, as fillers in the manufacture of tooth paste and powder, foods, cosmetics, pharmaceuticals and antibiotics. Technical grades are used in the manufacture of ceramics, putty, polishes, insecticides, inks, shoe dressings and as a filler in the production of adhesives, matches, linoleum and welding rods. To some extent it is also used as an extruded pigment in the paint industry. Major users of activated and precipitated calcium carbone is toothpaste industry, pharmaceutical industry, cosmetics, cement and rubber industry.