sedimentary

Flint or chert artifact

Microcrystalline quartz (SiO₂), likely worked flint/chert

AI-generated identification · may be incorrect

Dense, opaque tan-to-gray material with dull to waxy luster and conchoidal fracture; Mohs hardness about 7, no cleavage, cryptocrystalline quartz structure, and specific gravity around 2.6. The sharp, flaked edge and apparent percussion scars indicate deliberate knapping rather than ordinary breakage.

Identified September 11, 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 tool, but an archaeological age cannot be established from the image alone.

Uses & applications

Historically used for cutting tools, scrapers, arrowheads, and fire-starting; modern chert is used as aggregate and in geological collections. Archaeological artifacts may have substantial cultural value, subject to provenance and legal restrictions.

Geological facts

Flint is a dark, fine-grained variety of chert, while “chert” is the broader term. Freshly struck surfaces are typically sharper and glossier than weathered cortex.

Field identification & locations

Identify by hardness, glassy conchoidal fracture, and inability to scratch with a steel knife; the yellow-brown outer rind may be weathered cortex. Common worldwide, especially in chalk and limestone regions; professional authentication is needed for artifact claims.