sedimentary
Flint
Sedimentary cryptocrystalline quartz (SiO2)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, typically dark gray or black with a waxy to vitreous 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 to vitreous luster and conchoidal fracture.
Formation & geological history
Formed through chemical replacement of limestone or chalk by silica-rich solutions during the Cretaceous period.
Uses & applications
Historically used for producing sparks and sharp tools; currently utilized in decorative aggregates and ball mills.
Geological facts
Prehistoric humans heavily relied on flint for projectile points and cutting tools due to its predictable conchoidal fracture.
Field identification & locations
Identify by its sharp, curved edges and ability to scratch glass and produce sparks when struck with steel. Commonly found in chalk deposits worldwide.
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