sedimentary
Chert (Flint)
Silicon dioxide (SiO2)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, waxy to vitreous luster, conchoidal fracture with sharp edges, microcrystalline or cryptocrystalline quartz structure, colors range from grey, white, brown to black.
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Physical properties
Hardness of 7 on the Mohs scale, waxy to vitreous luster, conchoidal fracture with sharp edges, microcrystalline or cryptocrystalline quartz structure, colors range from grey, white, brown to black.
Formation & geological history
Forms via the chemical or biochemical precipitation of silica from aqueous solutions, often replacing calcium carbonate in limestone or chalk formations over geological time.
Uses & applications
Historically used for making stone tools and weapons due to its sharp conchoidal fracture; currently used in aggregate, abrasive products, and sometimes lapidary or decorative purposes.
Geological facts
Chert and flint are essentially the same material; the term 'flint' is commonly used for varieties found in chalk, while 'chert' is used for varieties found in limestone.
Field identification & locations
Easily identified by its hardness, smooth waxy appearance on freshly broken surfaces, and distinct conchoidal fracture. Found worldwide in sedimentary rock sequences.
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