Calcite
Chemical Formula	CaCO3
Species	Carbonates
Crystal System	Trigonal
Mohs Scale	3
Specific Gravity	2.71
Color	Colorless or white, also gray, yellow, green,red
Streak	White
Luster	Vitreous, Pearly
Refractive Index	n = 1.640 - 1.660 n = 1.486
Diaphaneity	Transparent, Translucent
Cleavage	PerfectPerfect on .
Fracture	Irregular/Uneven, Step-Like
Crystal Habit：Crystalline, granular, stalactitic, concretionary, massive, rhombohedral.
Geological Setting：Found in most geologic settings and as a later forming replacement mineral in most other environments in one form or another, it is most common as massive material in limestones and marbles. It forms as chemical sedimentary deposits as limestone, can be regionally or contact metamorphosed into marbles and rarely forms igneous rocks (carbonatites). Also is a common gangue mineral in hydrothermal deposits.