sedimentary
Flint
Cryptocrystalline Quartz (SiO2)
AI-generated identification · may be incorrectHardness of 7 on Mohs scale, dark gray to black color with a waxy luster, conchoidal fracture, and no cleavage.
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Physical properties
Hardness of 7 on Mohs scale, dark gray to black color with a waxy luster, conchoidal fracture, and no cleavage.
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-starting; today primarily used as a decorative aggregate and by historical reenactors.
Geological facts
Flint is extremely durable and breaks with sharp edges, making it the preferred material for prehistoric weaponry and cutting tools.
Field identification & locations
Identified by its conchoidal fracture, waxy luster, and ability to scratch glass; commonly found embedded in chalk formations worldwide.
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