sedimentary
Chert
Microcrystalline quartz (SiO2)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, dark gray to black color, waxy to vitreous luster, conchoidal fracture.
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Physical properties
Hardness of 7 on the Mohs scale, dark gray to black color, waxy to vitreous luster, conchoidal fracture.
Formation & geological history
Formed by the chemical precipitation of silica from seawater or replacement of limestone during deep-sea diagenesis.
Uses & applications
Historically used for making stone tools, arrowheads, and spark generation.
Geological facts
Chert breaks with extremely sharp edges, making it a preferred material for primitive stone weaponry.
Field identification & locations
Identify by its dense microcrystalline structure, smooth waxy feel, and characteristic conchoidal fracture.
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