sedimentary
Chert / Flint Nodule
Microcrystalline Quartz (SiO2)
Hardness of 7 on the Mohs scale, dull to waxy luster, crypto-crystalline structure, conchoidal fracture, colors range from grey, brown, white to black.
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Physical properties
Hardness of 7 on the Mohs scale, dull to waxy luster, crypto-crystalline structure, conchoidal fracture, colors range from grey, brown, white to black.
Formation & geological history
Formed through the chemical precipitation of silica from aqueous solutions or the replacement of limestone/chalk by silica-rich fluids over geological time.
Uses & applications
Historically used for making stone tools and weapons due to its sharp edges when fractured; currently collected as a geological specimen.
Geological facts
Ancient humans heavily utilized chert and flint for knapping arrowheads and blades because of its predictable conchoidal fracture.
Field identification & locations
Found worldwide in sedimentary sequences, particularly within chalk and limestone formations. Identify by its smooth, weathered exterior rind and typical conchoidal fracture.
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