sedimentary
Flint
Microcrystalline quartz (SiO2)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, typically gray or brown to black, with a waxy to vitreous luster and conchoidal fracture.
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Physical properties
Hardness of 7 on the Mohs scale, typically gray or brown to black, with a waxy to vitreous luster and conchoidal fracture.
Formation & geological history
Formed through 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 gravel.
Geological facts
Flint has been utilized by humans since the Stone Age due to its ability to fracture into extremely sharp edges.
Field identification & locations
Identify by its conchoidal fracture and hardness capable of scratching glass; commonly found inside chalk or limestone formations.
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