Calcite is the name give to a family of chemically related (CaCO3) stones. Calcite comes in numerous colours; clear, blue, green, orange and red. It can have a Vitreous, Sub-Vitreous, Resinous, Waxy, and Pearly lustre. All types of calcite have a hardness of 3 on the Mohs Scale. A Specific Gravity of 2.7102 and forms according to a hexagonal crystal system.