sedimentary
Chert
Microcrystalline quartz (SiO2)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, waxy luster, conchoidal fracture, various colors including brown, gray, and white.
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Physical properties
Hardness of 7 on the Mohs scale, waxy luster, conchoidal fracture, various colors including brown, gray, and white.
Formation & geological history
Formed through the chemical precipitation of silica from seawater or the replacement of limestone during diagenesis.
Uses & applications
Historically used for making stone tools and arrowheads due to its sharp edges when fractured.
Geological facts
Chert is extremely durable and often weathers out of limestone formations as nodules.
Field identification & locations
Identify by its conchoidal fracture, high hardness that scratches glass, and waxy appearance. Common worldwide.
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