Limestone
Image: <a href="//commons.wikimedia.org/wiki/User:Rosser1954" title="User:Rosser1954">Rosser1954</a> (Public domain)
Mineral NameLimestone
Chemical FormulaCaCO3
Mohs Hardness3
Crystal Systemtrigonal
Streak Colorwhite
Cleavageperfect rhombohedral (of calcite)
Fractureuneven/subconchoidal
Specific Gravity2.71
Colorswhite, gray, brown, black, yellow
Transparencyopaque
Type LocalityFound worldwide in sedimentary basins
Mineral GroupCarbonates (rock composed primarily of calcite)
Usesbuilding material, cement production, agricultural lime, dimension stone, flux in metallurgy
Associated Mineralscalcite, aragonite, dolomite, quartz, clay minerals, chert, fossils
Raritycommon
Description
The image displays dark, weathered limestone bedrock in a stream, characterized by smooth, water-eroded surfaces forming natural basins and channels. Patches of green moss cling to the exposed rock above the waterline, indicating a damp, outdoor environment.
Geological Context
Limestone is a sedimentary rock primarily composed of calcium carbonate, often formed from the accumulation of marine organism shells and skeletal fragments in shallow, warm marine environments. It is significant for its role in the carbon cycle and as a major reservoir rock for oil and gas.
