sedimentary
Limestone
Calcium Carbonate (CaCO3)
AI-generated identification · may be incorrectHardness of 3 on the Mohs scale, typically gray, tan, or white in color with an earthy to subvitreous luster, and an amorphous or fine-grained crystal structure.
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Physical properties
Hardness of 3 on the Mohs scale, typically gray, tan, or white in color with an earthy to subvitreous luster, and an amorphous or fine-grained crystal structure.
Formation & geological history
Formed through the accumulation of skeletal fragments from marine organisms like coral and mollusks in shallow marine environments over millions of years.
Uses & applications
Widely used in construction as building material, crushed stone for road bases, and as a primary raw ingredient in the production of cement.
Geological facts
Limestone frequently contains well-preserved fossils and dissolves slowly in acidic groundwater, creating dramatic karst landscapes and cave systems.
Field identification & locations
Easily identified by its characteristic reaction with hydrochloric acid, which causes it to vigorously effervesce or fizz.
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Other sedimentary specimens
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
fossil
Fossiliferous Sedimentary Rock
Sedimentary limestone with invertebrate fossil imprint
fossil
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sandstone
Arenite
sedimentary
Shale
Shale (clastic sedimentary rock)
sedimentary
Shale (or Mudstone/Siltstone)
Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
sedimentary