sedimentary

Flint (chert) with a flint knapping flake

Microcrystalline quartz (SiO₂), commonly called flint or chert

AI-generated identification · may be incorrect

Hardness about 7 Mohs; typically dull to waxy, with a fine-grained texture and conchoidal fracture. The pictured pieces appear brown to gray; crystal structure is too fine to see unaided.

Identified October 9, 2026More sedimentary →

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Physical properties

Hardness about 7 Mohs; typically dull to waxy, with a fine-grained texture and conchoidal fracture. The pictured pieces appear brown to gray; crystal structure is too fine to see unaided.

Formation & geological history

Forms when silica replaces or accumulates in sedimentary rocks, especially chalk and limestone. Flint occurs in rocks of many ages, so the specimen’s age cannot be determined from the image.

Uses & applications

Historically knapped into tools and weapons; today used for teaching, collecting, and occasionally decorative or lapidary work.

Geological facts

The sharp-edged flake and shaped piece are consistent with stone knapping, though their exact age and human origin cannot be confirmed visually.

Field identification & locations

Look for very fine texture, curved fracture scars, and sharp edges; common in chalk and limestone regions. The image alone does not establish the find location or archaeological context.