sedimentary
Flint
Cryptocrystalline Quartz (SiO2)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, typically dark gray or brown with a waxy to vitreous luster, displaying conchoidal fracture.
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Physical properties
Hardness of 7 on the Mohs scale, typically dark gray or brown with a waxy to vitreous luster, displaying conchoidal fracture.
Formation & geological history
Formed through the chemical replacement of calcium carbonate in limestone by silica-rich solutions over millions of years.
Uses & applications
Historically used for making stone tools and fire-starting; currently used in abrasives and decorative landscaping.
Geological facts
Ancient humans prized flint for its sharp conchoidal fracture, making it ideal for arrowheads and blades.
Field identification & locations
Easily identified by its waxy luster, sharp conchoidal edges, and occurrence as nodules within chalk or limestone formations.
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