sedimentary
Flint
SiO2 (Microcrystalline Quartz)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, typically brown, gray, or black with a waxy to vitreous luster. Features conchoidal fracture and a cryptocrystalline structure.
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Physical properties
Hardness of 7 on the Mohs scale, typically brown, gray, or black with a waxy to vitreous luster. Features conchoidal fracture and a cryptocrystalline structure.
Formation & geological history
Formed through the chemical replacement of limestone or chalk by silica-rich groundwaters during the Cretaceous period.
Uses & applications
Historically used for making stone tools, arrowheads, and fire-starting flintlocks; currently used in landscaping and abrasives.
Geological facts
Prehistoric humans heavily prized flint for its sharp edges when fractured, making it essential for early survival and toolmaking.
Field identification & locations
Identified easily by its sharp conchoidal fracture, waxy luster, and occurrence within chalk or limestone formations.
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