Coquina
Image: <a href="//commons.wikimedia.org/w/index.php?title=User:Lumasella&action=edit&redlink=1" class="new" title="User:Lumasella (page does not exist)">Lumasella</a> (CC BY-SA 3.0)
Mineral NameCoquina
Chemical FormulaCaCO3
Mohs Hardness3
Crystal Systemamorphous
Streak Colorwhite
Cleavagenot applicable (rock)
Fractureuneven/earthy
Specific Gravity2.7
Colorswhite, beige, yellowish-brown, grey
Transparencyopaque
Type LocalityOdessa, Ukraine
Mineral GroupSedimentary rock (Limestone, Carbonate group)
Usesbuilding material, road aggregate, decorative stone
Associated Mineralscalcite, aragonite, quartz, clay minerals
Raritycommon
Description
This rock is a light-colored, porous mass densely packed with fragmented and whole bivalve shells, exhibiting a rough, uneven texture.
Geological Context
Coquina is a clastic sedimentary rock formed in shallow marine environments, typically from the rapid accumulation and cementation of shell fragments, often indicating high-energy depositional settings during the Pleistocene epoch.
