sedimentary

Chert (Flint flake / debitage)

Microcrystalline / Cryptocrystalline Quartz (SiO2)

AI-generated identification · may be incorrect

Hardness 7 on Mohs scale; light tan to buff gray color; dull to slightly waxy luster; conchoidal to subconchoidal fracture; dense, cryptocrystalline texture with sharp fractured edges.

Identified October 26, 2026More sedimentary →

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Physical properties

Hardness 7 on Mohs scale; light tan to buff gray color; dull to slightly waxy luster; conchoidal to subconchoidal fracture; dense, cryptocrystalline texture with sharp fractured edges.

Formation & geological history

Formed through biochemical and chemical precipitation of microcrystalline silica in marine sedimentary environments, often within limestone or chalk beds, or by replacement of carbonate minerals by silica-rich fluids.

Uses & applications

Historically used for knapping stone tools, projectile points, and fire-striking due to its predictable conchoidal fracture and razor-sharp edges. Modernly used in road aggregate, abrasives, and as collectible lithic material.

Geological facts

This piece has a triangular shape reminiscent of a projectile point or lithic flake (tool-making debitage/preform). Chert and flint were among the very first raw materials harvested and shaped by prehistoric humans worldwide.

Field identification & locations

Identified by its high hardness (scratches glass/steel), lack of visible grains, dull to waxy appearance, and conchoidal fracture. Found widely in limestone terrains, gravel beds, and riverbars globally.