sedimentary

Small flint/chert fragment (tentative)

Chert, microcrystalline quartz (SiO₂)

AI-generated identification · may be incorrect

A small, irregular gray-brown fragment with a pale, rough edge; the image does not show enough detail to confirm its material. If chert, it has Mohs hardness about 7, a waxy-to-dull luster, no cleavage, and a dense, fine-grained structure.

Identified October 4, 2026More sedimentary →

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Physical properties

Formation & geological history

Chert forms when silica accumulates or replaces material in sedimentary settings, often in limestone or chalk; its age varies widely with the host rock.

Uses & applications

Chert has historically been knapped for sharp tools and can be used as aggregate or collected as a geological specimen.

Geological facts

Freshly fractured chert commonly displays curved, shell-like (conchoidal) breaks and sharp edges.

Field identification & locations

Look for hardness, a smooth conchoidal fracture, and resistance to scratching by a steel knife; the pictured fragment alone is not diagnostic. Chert occurs worldwide in sedimentary rocks.