sedimentary
Flint
Microcrystalline Quartz (SiO2)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, typically gray or tan 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 tan with a waxy to vitreous luster and conchoidal fracture.
Formation & geological history
Formed via the chemical replacement of calcium carbonate by silica-rich solutions within chalk or limestone formations during the Cretaceous period.
Uses & applications
Historically used for making stone tools and fire-starting; currently used in decorative landscaping and occasionally as a tumbling stone.
Geological facts
Flint is extremely durable and breaks with sharp edges, making it the primary material for prehistoric weapons.
Field identification & locations
Identify by its conchoidal fracture, waxy feel, and ability to scratch glass. Commonly found in chalk deposits worldwide.
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