Image: Photo by and (c)2015 Derek Ramsey (<a href="https://en.wikipedia.org/wiki/User:Ram-Man" class="extiw" title="en:User:Ram-Man">Ram-Man</a>) (CC BY-SA 4.0)
trigonalcommonCarbonates
Calcite
CaCO3
This specimen features white, translucent, well-formed calcite crystals, likely rhombohedral, growing on a matrix of purple amethyst quartz.
Calcite Physical Properties
Mohs Hardness
3Crystal System
trigonalLuster
vitreousStreak Color
whiteCleavage
Perfect rhombohedral in three directionsFracture
conchoidalSpecific Gravity
2.71Colors
white, colorless, yellow, pink, green, blue, brownTransparency
transparentType Locality
Worldwide, notably Mexico, Iceland, USAMineral Group
CarbonatesUses
cement production, agricultural lime, optical instruments, carving, architectural stoneAssociated Minerals
amethyst quartzRarity
commonGeological Context
Calcite is a very common mineral found in sedimentary rocks (limestone, marble), hydrothermal veins, and as a secondary mineral in igneous and metamorphic rocks. It forms from the precipitation of calcium carbonate from water.
