sedimentary
Flint (Chert)
Silicon Dioxide (SiO2)
Hardness of 7 on the Mohs scale, waxy or vitreous luster, conchoidal fracture, opaque to translucent, colors range from grey, brown, white, to black.
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Physical properties
Hardness of 7 on the Mohs scale, waxy or vitreous luster, conchoidal fracture, opaque to translucent, colors range from grey, brown, white, to black.
Formation & geological history
Formed through the replacement of calcium carbonate by silica-rich solutions in limestone or chalk formations during the Cretaceous and other sedimentary periods.
Uses & applications
Historically used for making stone tools, arrowheads, and striking fire; currently used in abrasives, landscaping, and decorative purposes.
Geological facts
Flint was crucial for human survival during the Stone Age due to its ability to break with sharp edges (conchoidal fracture) and create sparks when struck against steel.
Field identification & locations
Easily identified by its smooth, nodular outer cortex, conchoidal fracture exposing a glass-like interior, and high hardness capable of scratching glass.
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