a colourless or white mineral (occasionally tinged with impurities), found in sedimentary and metamorphic rocks, in veins, in limestone, and in stalagmites and stalactites. It is used in the manufacture of cement, plaster, paint, glass, and fertilizer. Composition: calcium carbonate. Formula: CaCO 3 . Crystal structure: hexagonal (rhombohedral)
crystalling calcium carbonate, 1849, from German Calcit, coined by Austrian mineralogist Wilhelm Karl von Hardinger (1795-1871) from Latin calx (genitive calcis) "lime" (see chalk (n.)) + mineral suffix -ite (2) (German -it).
A usually white, clear, pale-yellow or blue orthorhombic mineral. Calcite occurs in many different forms and is the main component of chalk, limestone, and marble. It is a polymorph of aragonite. Chemical formula: CaCO3.