sedimentary
Limestone
Calcium Carbonate (CaCO3)
AI-generated identification · may be incorrectMohs hardness of 3; colors range from white and gray to tan; earthy to vitreous luster; massive or fine-grained crystal structure; good cleavage in three directions (rhombohedral).
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Physical properties
Mohs hardness of 3; colors range from white and gray to tan; earthy to vitreous luster; massive or fine-grained crystal structure; good cleavage in three directions (rhombohedral).
Formation & geological history
Formed through the accumulation and compaction of organic remains like shells and coral, or chemical precipitation in shallow marine environments over millions of years.
Uses & applications
Extensively used in construction as building stone, as an aggregate for road bases, in the manufacturing of cement, and in agricultural soil treatment.
Geological facts
Limestone frequently contains well-preserved fossils and forms dramatic surface landscapes known as karst topography, featuring caves and sinkholes.
Field identification & locations
Readily identified by its characteristic reaction with dilute hydrochloric acid, producing effervescence due to carbon dioxide release.
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Fossil-bearing concretion, possibly containing a fossil shell or other organic inclusion
Calcareous concretion; exact fossil and host-rock composition are not identifiable from the image
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Fossiliferous Sedimentary Rock
Sedimentary limestone with invertebrate fossil imprint
fossil
Sandstone or Siltstone
Arenite (if sandstone)
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Sandstone
Arenite
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Shale
Shale (clastic sedimentary rock)
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Shale (or Mudstone/Siltstone)
Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
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