sedimentary
Flint
SiO2 (Cryptocrystalline Quartz)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, waxy to vitreous luster, conchoidal fracture, and typically grey, black, or dark brown in color.
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Physical properties
Hardness of 7 on the Mohs scale, waxy to vitreous luster, conchoidal fracture, and typically grey, black, or dark brown in color.
Formation & geological history
Formed through the replacement of calcium carbonate by silica-rich solutions in chalk or limestone formations during the Cretaceous period.
Uses & applications
Historically used for prehistoric stone tools and fire-starting; currently utilized in abrasives and decorative landscaping.
Geological facts
Flint produces sparks when struck against steel due to its extreme hardness and microcrystalline structure.
Field identification & locations
Identified easily by its sharp conchoidal fracture edges and waxy luster; commonly found embedded in chalk cliffs worldwide.
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