sedimentary

Chert (Jasper variety)

Microcrystalline Quartz (SiO2)

AI-generated identification · may be incorrect

Hardness: 6.5-7 on Mohs scale; Color: Brownish-yellow and dark grey; Luster: Dull to waxy; Structure: Cryptocrystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 6
Color: Brownish-yellow and dark grey
Luster: Dull to waxy

Identified June 18, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 on Mohs scale; Color: Brownish-yellow and dark grey; Luster: Dull to waxy; Structure: Cryptocrystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed through the accumulation of silica-rich organic remains or chemical precipitation in marine environments. This specimen appears water-worn, likely from a river or beach deposit.

Uses & applications

Historically used for stone tools due to sharp edges; currently used for decorative gravel, landscaping, and as a lapidary material for tumbling and cabochons.

Geological facts

Chert is essentially the same mineral as flint, but the name 'Jasper' is applied to opaque varieties. It is extremely durable and chemically resistant to weathering.

Field identification & locations

Identifiable in the field by its hardness (will scratch glass), conchoidal (shell-like) fracture patterns, and smooth, waxy surface when wet. Commonly found in gravel pits and along shorelines.