Calcite
Image: Thomas Bresson (CC BY 4.0)
Mineral NameCalcite
Chemical FormulaCaCO3
Mohs Hardness3
Crystal Systemtrigonal
Lustervitreous
Streak Colorwhite
Cleavageperfect rhombohedral in three directions
Fractureconchoidal to uneven
Specific Gravity2.71
Colorswhite, yellowish-white, cream
Transparencytranslucent
Type LocalityWorldwide
Mineral GroupCarbonates
Usescement, construction, agriculture, optical instruments, collector
Associated Mineralsquartz, fluorite, barite, galena, sphalerite
Raritycommon
Description
The image shows a granular, botryoidal aggregation of pale yellowish-white calcite crystals, forming a textured, somewhat lumpy surface. The individual crystals are small and appear to be intergrown.
Geological Context
Calcite is a very common mineral found in sedimentary rocks (limestone, marble), as a vein mineral, and as a primary component of speleothems in caves. It precipitates from aqueous solutions.
