sedimentary
Chert
Microcrystalline quartz (SiO2)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, earthy to waxy luster, conchoidal fracture, and colors ranging from brown to gray.
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Physical properties
Hardness of 7 on the Mohs scale, earthy to waxy luster, conchoidal fracture, and colors ranging from brown to gray.
Formation & geological history
Formed through the accumulation of siliceous microfossil remains or chemical precipitation in marine environments over millions of years.
Uses & applications
Historically used for making stone tools and arrowheads due to its sharp edges when fractured.
Geological facts
Chert weathers down easily into distinctive blocky shapes and produces bright sparks when struck against steel.
Field identification & locations
Identify in the field by its hardness, dense structure, and characteristic conchoidal fracture patterns.
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Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
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