Crinoid Limestone
Image: <a href="//commons.wikimedia.org/wiki/User:Hans_Erren" title="User:Hans Erren">Hans Erren</a> (CC BY-SA 3.0)
Mineral NameCrinoid Limestone
Chemical FormulaCaCO3
Mohs Hardness3
Lusterdull
Streak ColorWhite
CleavagePerfect rhombohedral (for calcite)
FractureUneven
Specific Gravity2.7
Colorsdark grey, light grey, white
TransparencyOpaque
Type LocalityBelgium
Mineral GroupSedimentary Rock
Usesbuilding material, dimension stone, cement production, agricultural lime
Associated Mineralscalcite, aragonite, clay minerals, quartz
Raritycommon
Description
A dark grey sedimentary rock composed of a fine-grained matrix densely packed with numerous light-colored fossil fragments, predominantly crinoid ossicles.
Geological Context
This bioclastic limestone forms in shallow marine environments where crinoids and other marine organisms thrive, their skeletal remains accumulating and compacting over millions of years.
