sedimentary
Chert
Silicon dioxide (SiO2)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, waxy luster, conchoidal fracture, and colors ranging from grey to brown or white.
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Physical properties
Hardness of 7 on the Mohs scale, waxy luster, conchoidal fracture, and colors ranging from grey to brown or white.
Formation & geological history
Formed by the chemical precipitation of silica from seawater or the accumulation of siliceous microfossil remains over millions of years.
Uses & applications
Historically used for making stone tools and weapons due to its sharp edges when fractured; occasionally used for decorative landscaping and tumbling.
Geological facts
Chert is extremely durable and weather-resistant, frequently outlasting the surrounding limestone matrix in which it often forms.
Field identification & locations
Identify by its distinct conchoidal fracture, hard scratch resistance against steel, and waxy or glassy surface appearance.
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Fossil-bearing concretion, possibly containing a fossil shell or other organic inclusion
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Sandstone or Siltstone
Arenite (if sandstone)
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Fossiliferous Sedimentary Rock
Sedimentary limestone with invertebrate fossil imprint
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Sandstone
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Shale (clastic sedimentary rock)
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Shale (or Mudstone/Siltstone)
Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
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