Calcite
Image: <a rel="nofollow" class="external text" href="https://www.flickr.com/people/25326737@N00">Jarno</a> from Rotterdam, Netherlands (CC BY 2.0)
Mineral NameCalcite
Chemical FormulaCaCO3
Mohs Hardness3
Crystal Systemtrigonal
Lustervitreous
Streak Colorwhite
Cleavageperfect rhombohedral in three directions
Fractureconchoidal to uneven
Specific Gravity2.71
Colorsyellow, colorless, white, pink, green, blue, brown, black
Transparencytransparent to translucent
Type LocalityWidespread globally, found in numerous geological settings
Mineral GroupCarbonates
Usescement production, flux in metallurgy, optical instruments (Iceland spar), soil conditioner, building material, collector specimens
Associated Mineralsquartz, fluorite, barite, pyrite, galena, sphalerite, dolomite
Raritycommon
Description
This image displays a cluster of beautiful yellow calcite crystals, exhibiting their characteristic rhombohedral forms and a vitreous luster. The crystals appear translucent, allowing some light to pass through.
Geological Context
Calcite is a ubiquitous mineral, forming in diverse geological environments including sedimentary rocks (limestone, chalk), metamorphic rocks (marble), hydrothermal veins, and as a secondary mineral in igneous rocks. It is the primary component of shells and skeletons of many marine organisms.
