Calcite
Image: <a rel="nofollow" class="external text" href="https://www.flickr.com/people/36519414@N00">Thomas Bresson</a> from Belfort, France (CC BY 2.0)
Mineral NameCalcite
Chemical FormulaCaCO₃
Mohs Hardness3
Crystal Systemtrigonal
Lustervitreous
Streak Colorwhite
Cleavageperfect rhombohedral
Fractureconchoidal
Specific Gravity2.71
Colorscolorless, white, light brown
Transparencytranslucent
Type LocalityEtretat, France
Mineral GroupCarbonates
Usesindustrial, construction, collector
Associated Mineralschalk, flint, marcasite
Raritycommon
Description
A vug within a pebble is lined with numerous small, sparkling, translucent crystals, ranging from colorless to light brown, forming a druzy texture.
Geological Context
Calcite frequently forms in sedimentary rocks like chalk, precipitating from circulating groundwater into pre-existing cavities and fractures within the rock.
