sedimentary

Banded Chert (Flint)

Microcrystalline Quartz (SiO2)

AI-generated identification · may be incorrect

Hardness: 7 on Mohs scale; Color: Cream, grey, and charcoal banding; Luster: Waxy to vitreous; Crystal structure: Cryptocrystalline; Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Cream, grey, and charcoal banding
Luster: Waxy to vitreous

Identified February 14, 2026More sedimentary →

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Physical properties

Hardness: 7 on Mohs scale; Color: Cream, grey, and charcoal banding; Luster: Waxy to vitreous; Crystal structure: Cryptocrystalline; Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Formation & geological history

Formed through the accumulation of silica-rich organic remains (like radiolaria or diatoms) or chemical precipitation in marine environments. This specimen shows typical water-worn rounding, likely from a riverbed or coastal area.

Uses & applications

Historically used for stone tools and weapons due to sharp edges; currently used for decorative stones, landscaping, and as a material for fire-starting (flint and steel).

Geological facts

Chert behaves like glass when broken, creating 'flakes' with edges sharper than a steel scalpel. It is one of the most common materials found at archaeological sites worldwide because of its durability.

Field identification & locations

Identify by its 'waxy' texture and curved, glass-like (conchoidal) fractures. It will easily scratch glass but cannot be scratched by a steel knife. Common in limestone regions and river gravels.