sedimentary
Chert
Silicon Dioxide (SiO2)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, waxy luster, conchoidal fracture, and typically black, brown, or grey in color.
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Physical properties
Hardness of 7 on the Mohs scale, waxy luster, conchoidal fracture, and typically black, brown, or grey in color.
Formation & geological history
Formed via the accumulation of siliceous microfossil skeletal remains or chemical precipitation in marine environments.
Uses & applications
Historically used for making stone tools and weapons due to its sharp conchoidal fracture.
Geological facts
Chert is extremely durable and often weathers out of limestone formations as nodules.
Field identification & locations
Identify by its hard waxy surface, sharp edges when broken, and inability to be scratched by steel.
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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)
sedimentary
Shale (or Mudstone/Siltstone)
Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
sedimentary