sedimentary
Chert
Microcrystalline quartz (SiO2)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, waxy luster, conchoidal fracture, and colors ranging from white to gray and black.
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Physical properties
Hardness of 7 on the Mohs scale, waxy luster, conchoidal fracture, and colors ranging from white to gray and black.
Formation & geological history
Formed through the chemical precipitation of silica in marine environments or replacement of limestone over millions of years.
Uses & applications
Historically used for making stone tools and arrowheads due to its sharp edges when fractured; occasionally used in ornamental lapidary work.
Geological facts
Chert has been utilized by humans globally since the Stone Age for creating fire with steel and fashioning durable cutting implements.
Field identification & locations
Identified easily by its conchoidal fracture and high hardness that scratches glass; commonly found within chalk or limestone formations.
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