Calcite

Formula	CaCO3
Origin	Gordonsville Mine (USA)
Description	several calcite scalenohedra on matrix
Classification (Lapis)	Carbonates
Crystal System	hexagonal
Hardness	3,0
Colour	cochineal-red, ruby-red, purplish red, to nearly black
Streak	white
Luminescence	frequently
Luster	vitreous
Transparency (Opacity)	transparent to opaque
Cleavage	perfect
Fracture	conchoidal
Magnetism	negative
Geological Setting	a major rock-forming mineral; in limestones, marbles, chalks, a common cement in clastic sedimentary rocks, and as gangue in hydrothermal veins
Specific Gravity	2,71 g/cm3