sedimentary
Flint
SiO2 (Cryptocrystalline Quartz)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, dark gray to black color, waxy to vitreous luster, and conchoidal fracture.
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Physical properties
Hardness of 7 on the Mohs scale, dark gray to black color, waxy to vitreous luster, and conchoidal fracture.
Formation & geological history
Formed through the chemical replacement of limestone or chalk by silica-rich solutions during the Cretaceous period.
Uses & applications
Historically used for producing sparks in fire-starting tools and making stone age weapons; currently used in decorative landscaping and knapping.
Geological facts
Flint is a hard variety of the mineral quartz and produces sharp edges when fractured, making it ideal for ancient tools.
Field identification & locations
Identify by its conchoidal fracture, waxy luster, and ability to scratch glass easily. Commonly found embedded in chalk formations.
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Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
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