sedimentary
Flint
Microcrystalline quartz (SiO2)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, typically gray or dark brown, waxy to vitreous luster, and conchoidal fracture.
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Physical properties
Hardness of 7 on the Mohs scale, typically gray or dark brown, waxy to vitreous luster, and conchoidal fracture.
Formation & geological history
Formed by the replacement of calcium carbonate by silica-rich solutions in chalk or limestone formations over millions of years.
Uses & applications
Historically used for making stone tools and fire-starting; currently used in decorative landscaping and abrasive grit.
Geological facts
Flint was crucial for ancient human survival due to its ability to hold a sharp edge when fractured.
Field identification & locations
Identify by its distinctive conchoidal fracture and lack of reaction to acid; commonly found within chalk deposits worldwide.
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