sedimentary
Chert / Flint
Microcrystalline Quartz (SiO2)
AI-generated identification · may be incorrectHardness 6.5-7 on the Mohs scale, typically gray, white, brown, or black with a waxy to dull luster. Exhibits conchoidal fracture when broken.
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Physical properties
Hardness 6.5-7 on the Mohs scale, typically gray, white, brown, or black with a waxy to dull luster. Exhibits conchoidal fracture when broken.
Formation & geological history
Formed through the accumulation of silica-rich marine microfossils or precipitation of silica in sedimentary environments like limestone or chalk deposits.
Uses & applications
Historically used for making stone tools and sparking fires due to its hardness and conchoidal fracture. Sometimes used as a low-grade aggregate or in lapidary arts.
Geological facts
Flint, a variety of chert, was essential to early human survival for tool making and fire starting.
Field identification & locations
Identified by its dense, fine-grained texture, conchoidal fracture, and ability to scratch glass. Commonly found as nodules in sedimentary rock formations globally.
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