sedimentary
Flint
SiO2 (Microcrystalline Quartz)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, typically dark grey or brown in color, waxy to vitreous luster, and displays conchoidal fracture with no cleavage.
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Physical properties
Hardness of 7 on the Mohs scale, typically dark grey or brown in color, waxy to vitreous luster, and displays conchoidal fracture with no cleavage.
Formation & geological history
Formed as nodules in sedimentary rocks like chalk or limestone through the replacement of calcium carbonate by silica-rich solutions.
Uses & applications
Historically used for making stone tools, weapons, and fire-starting flintlocks; currently used in abrasives and decorative gravel.
Geological facts
Flint has been utilized by humans for over two million years due to its sharp edges when fractured. It is functionally a variety of chert.
Field identification & locations
Identified easily by its conchoidal fracture, waxy luster, and ability to produce sparks when struck with steel. Commonly found in chalk deposits worldwide.
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