sedimentary

Likely banded chert (flint) fragment

Microcrystalline quartz, SiO₂; visual identification is uncertain from the image alone

AI-generated identification · may be incorrect

Pale gray to tan, elongated piece with subtle parallel bands and a dull-to-waxy surface. Quartz has Mohs hardness 7, a trigonal crystal structure at microscopic scale, and no cleavage; chert commonly breaks with curved, sharp edges.

Identified October 13, 2026More sedimentary →

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Physical properties

Formation & geological history

Chert forms when silica accumulates and recrystallizes in sedimentary settings, often in limestone or chalk. Its age varies widely and cannot be determined from the photograph.

Uses & applications

Chert has historically been used for sharp tools and fire-starting; attractive banded pieces are collected or used decoratively.

Geological facts

Chert is composed of extremely fine quartz crystals, so individual crystals are generally invisible without magnification.

Field identification & locations

The piece may be chert, but the image does not show diagnostic features clearly enough for a confident identification. Check for a hard, glass-scratching surface and a sharp, curved fracture; common sources include sedimentary formations and gravel deposits.