sedimentary
Chert Pebble
Cryptocrystalline quartz (SiO2)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, earthy to waxy luster, conchoidal fracture, and typically gray, white, or brown coloration.
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Physical properties
Hardness of 7 on the Mohs scale, earthy to waxy luster, conchoidal fracture, and typically gray, white, or brown coloration.
Formation & geological history
Formed through the chemical precipitation of silica in marine environments or the replacement of limestone over millions of years.
Uses & applications
Historically used for making stone tools and arrowheads due to its sharp edges when fractured.
Geological facts
Chert is exceptionally durable and weather-resistant, allowing it to survive river transport as smooth pebbles.
Field identification & locations
Identify by its conchoidal fracture, high hardness that scratches glass, and smooth water-worn exterior in riverbeds.
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