sedimentary
Flint
Cryptocrystalline quartz (SiO2)
AI-generated identification · may be incorrectHardness 7 on Mohs scale, waxy luster, conchoidal fracture, colors range from dark brown to grey and white.
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Physical properties
Hardness 7 on Mohs scale, waxy luster, conchoidal fracture, colors range from dark brown to grey and white.
Formation & geological history
Formed via the replacement of calcium carbonate by silica-rich solutions in chalk or limestone formations during the Cretaceous period.
Uses & applications
Historically used for making stone tools and fire-starting; currently used in decorative aggregates and abrasive blasting.
Geological facts
Flint knapping produces extremely sharp edges, making it one of the earliest advanced technologies utilized by hominids.
Field identification & locations
Identify in the field by its conchoidal fracture, waxy luster, and high hardness that scratches glass. Commonly found in chalk deposits worldwide.
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