sedimentary

Chert (flint), likely a knapped piece

Microcrystalline quartz (SiO₂), commonly called chert or flint

AI-generated identification · may be incorrect

White to pale gray, waxy luster, opaque to slightly translucent edges, and conchoidal fracture; Mohs hardness about 7. The flake-like shape and sharp ridges suggest it has been deliberately chipped.

Identified October 15, 2026More sedimentary →

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Physical properties

White to pale gray, waxy luster, opaque to slightly translucent edges, and conchoidal fracture; Mohs hardness about 7. The flake-like shape and sharp ridges suggest it has been deliberately chipped.

Formation & geological history

Forms when silica accumulates and replaces material in sedimentary settings, often in limestone or chalk; its age depends on the host formation. The visible shape appears to result from later human knapping, not natural crystal growth.

Uses & applications

Chert was widely used for prehistoric tools and projectile points; today it is collected or used as a source of sharp flakes and, less commonly, in decorative objects.

Geological facts

Chert breaks into very sharp edges with curved, shell-like fracture surfaces, making it useful for cutting tools.

Field identification & locations

Look for hardness, a waxy surface, and conchoidal fracture; it does not fizz in dilute acid. Chert occurs worldwide, especially in sedimentary limestone and chalk regions; this specimen’s exact locality and whether it is an artifact cannot be confirmed from the image.