sedimentary
Flint
Cryptocrystalline Quartz (SiO2)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, typically brown or gray, waxy to vitreous luster, and conchoidal fracture.
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Physical properties
Hardness of 7 on the Mohs scale, typically brown or gray, waxy to vitreous luster, and conchoidal fracture.
Formation & geological history
Formed by the chemical replacement of limestone or chalk by silica-rich groundwater over millions of years.
Uses & applications
Historically used for making stone tools and fire-starting; currently used in abrasives and decorative landscaping.
Geological facts
Prehistoric humans heavily relied on flint due to its ability to fracture into extremely sharp edges.
Field identification & locations
Identify by its conchoidal fracture, waxy luster, and ability to scratch glass; commonly found embedded in chalk formations.
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