sedimentary
Chert
Cryptocrystalline 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 the replacement of limestone by silica-rich solutions.
Uses & applications
Historically used by early humans for making stone tools and arrowheads due to its sharp conchoidal fracture.
Geological facts
Chert that is dark or black is commonly referred to as flint. It is extremely durable and resistant to weathering.
Field identification & locations
Identify by its hard waxy surface, smooth conchoidal breakage patterns, and ability to scratch glass. Found worldwide in limestone formations.
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Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
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