Calcite is an abundant mineral composed primarily of calcium carbonate (CaCO₃) distinguished by its hardness of 3 on the Mohs scale, its effervescence with acids, its birefringence, and a wide variety of colors. It forms in diverse geological environments (sedimentary, metamorphic, and hydrothermal) and has multiple industrial uses, such as the manufacture of cement and lime, as well as in the production of paper, plastics, glass, and in water treatment.