sedimentary
Flint
Cryptocrystalline Quartz (SiO2)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, typically dark gray or black with a waxy luster and conchoidal fracture.
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Physical properties
Hardness of 7 on the Mohs scale, typically dark gray or black with a waxy luster and conchoidal fracture.
Formation & geological history
Formed through the replacement of calcium carbonate by silica-rich solutions in chalk or limestone formations.
Uses & applications
Historically used for making stone tools and fire-starting; currently used in decorative landscaping and aggregates.
Geological facts
Prehistoric humans heavily favored flint for making sharp blades and projectile points due to its predictable conchoidal fracture.
Field identification & locations
Identify by its dark color, conchoidal fracture, and ability to spark when struck with steel; found worldwide in chalk deposits.
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