sedimentary
Flint
SiO2 (Microcrystalline Quartz)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, waxy to vitreous luster, conchoidal fracture, and typically gray to dark brown with a chalky cortex.
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Physical properties
Hardness of 7 on the Mohs scale, waxy to vitreous luster, conchoidal fracture, and typically gray to dark brown with a chalky cortex.
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 making stone tools and fire-starting; currently valued by collectors and historical reenactors.
Geological facts
Flint played a critical role in human technological development during the Stone Age due to its sharp edges when fractured.
Field identification & locations
Identify by its conchoidal fracture, waxy luster, and ability to produce sparks when struck against steel. Commonly found in chalk deposits worldwide.
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Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
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