sedimentary
Flint
Silicon Dioxide (SiO2)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, waxy luster, conchoidal fracture, and typically dark gray to brown or black color.
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Physical properties
Hardness of 7 on the Mohs scale, waxy luster, conchoidal fracture, and typically dark gray to brown or black color.
Formation & geological history
Formed through the chemical replacement of calcium carbonate in limestone or chalk by silica-rich solutions during the Cretaceous period.
Uses & applications
Historically used for making stone tools and fire-starting flint-locks; modern applications include abrasive grit and decorative landscaping.
Geological facts
Ancient humans prized flint for its sharp conchoidal edges, which make it ideal for blades and arrowheads.
Field identification & locations
Identify in the field by its distinct conchoidal fracture and hardness that easily scratches glass; commonly found embedded in chalk and limestone deposits worldwide.
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Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
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