sedimentary
Chert
Microcrystalline quartz (SiO2)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, waxy luster, conchoidal fracture, and colors ranging from white to brown and grey.
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Physical properties
Hardness of 7 on the Mohs scale, waxy luster, conchoidal fracture, and colors ranging from white to brown and grey.
Formation & geological history
Formed through the chemical precipitation of silica from seawater or replacement of limestone during the Cretaceous period.
Uses & applications
Historically used for making stone tools and arrowheads; currently utilized in aggregate and abrasives.
Geological facts
Chert is exceptionally durable and breaks with razor-sharp edges, making it ideal for primitive weaponry.
Field identification & locations
Identify by its conchoidal fracture and high hardness that scratches glass easily; commonly found in limestone deposits worldwide.
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Fossiliferous Sedimentary Rock
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Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
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