sedimentary

Flint or chert knapped tool/flake

Microcrystalline quartz (SiO₂), likely chert/flint

AI-generated identification · may be incorrect

Dark gray to black, opaque, dull-to-waxy luster, very fine-grained with conchoidal fracture and sharp chipped edges; Mohs hardness about 7, no cleavage, specific gravity ~2.6. The shape and flake scars suggest intentional knapping rather than a natural fragment.

Identified August 15, 2026More sedimentary →

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Physical properties

Formation & geological history

Chert forms when silica replaces or accumulates in sedimentary rocks, commonly limestone, during diagenesis; its age depends on the host formation. This specimen appears human-worked, possibly a prehistoric flake or small point, though the image alone cannot establish age or authenticity.

Uses & applications

Raw chert is used for toolmaking, fire-starting, aggregate, and decorative stone; archaeological flakes are valued as artifacts rather than for industrial use.

Geological facts

Conchoidal fracture produces exceptionally sharp edges, historically used for cutting and striking sparks. Black flint is especially common in chalk and limestone regions.

Field identification & locations

Look for continuous flake scars, a striking platform, bulb of percussion, and sharp retouched margins; natural breaks are usually less patterned. Common worldwide, especially Europe, the Middle East, and North America.