sedimentary
Flint
Sedimentary cryptocrystalline quartz (SiO2)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, colors ranging from grey to dark brown, waxy to vitreous luster, and conchoidal fracture.
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Physical properties
Hardness of 7 on the Mohs scale, colors ranging from grey to dark brown, waxy to vitreous luster, and conchoidal fracture.
Formation & geological history
Formed through the chemical replacement of limestone or chalk by silica-rich solutions during the Cretaceous period.
Uses & applications
Historically used for making stone tools and fire-striking; currently collected as a geological specimen.
Geological facts
Flint was crucial for early human technological development due to its sharp edges when fractured.
Field identification & locations
Identify in the field by its conchoidal fracture and chalky outer cortex, commonly found within chalk deposits worldwide.
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