Pure calcite is transparent or white, but a variety of impurities can give this mineral certain colors. Calcite in the form of limestone is the chief source of lime.
Limestone also serves as a raw material in cement and mortar and as a building stone.
Pure calcite is a form of calcium carbonate. Calcite crystals can split into perfect rhombohedrons, six-sided objects in which the opposite sides are parallel. Because of its softness, calcite serves as a scratchless scouring ingredient in some cleaning powders. Calcite fizzes in a weak acid solution. Some beaches in Florida along the Gulf of Mexico consist primarily of calcite shells and coral from marine invertebrates.