sedimentary

Chert (likely flint)

Microcrystalline quartz, SiO₂

AI-generated identification · may be incorrect

Tan to honey-brown, opaque to slightly translucent edges, with a waxy luster and irregular conchoidal fracture; Mohs hardness 7. The small fragment’s identification is tentative from the image.

Identified October 13, 2026More sedimentary →

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Physical properties

Tan to honey-brown, opaque to slightly translucent edges, with a waxy luster and irregular conchoidal fracture; Mohs hardness 7. The small fragment’s identification is tentative from the image.

Formation & geological history

Forms when silica accumulates and replaces material in sedimentary settings, commonly as nodules in limestone or chalk; the specimen’s age and exact source cannot be determined visually.

Uses & applications

Chert has been used for sharp-edged tools and fire-starting; attractive pieces are collected, but this fragment appears to have little commercial value.

Geological facts

Its very fine quartz crystals are too small to distinguish without magnification, and fresh fractures can be exceptionally sharp.

Field identification & locations

Look for hardness sufficient to scratch glass and curved, shell-like fracture surfaces; common worldwide in sedimentary rocks. The image shows a small, weathered-looking fragment, not enough to confirm flint versus other chert.