sedimentary

Chert (Jasper)

Microcrystalline Quartz (SiO2)

Hardness: 6.5-7 on Mohs scale. Color: Brownish-red to liver-brown. Luster: Dull to waxy. Crystal structure: Cryptocrystalline. Cleavage: None (conchoidal fracture). Specific Gravity: 2.6-2.7.

Hardness: 6
Color: Brownish-red to liver-brown
Luster: Dull to waxy

Identified July 10, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 on Mohs scale. Color: Brownish-red to liver-brown. Luster: Dull to waxy. Crystal structure: Cryptocrystalline. Cleavage: None (conchoidal fracture). Specific Gravity: 2.6-2.7.

Formation & geological history

Formed via the accumulation of silica-rich organic remains or chemical precipitation in marine or groundwater environments. Often found in nodules or bedded deposits within limestone or dolomite.

Uses & applications

Used historically for stone tools (knapping) due to its sharp edges. Today used for lapidary work, jewelry (as jasper), and as an decorative landscape stone.

Geological facts

Brown chert is often referred to as 'liver stone' based on its color. It is extremely durable and can survive millions of years of river transport and weathering.

Field identification & locations

Identify by its smooth, waxy texture and shell-like (conchoidal) fracture patterns. It will scratch glass but cannot be scratched by a steel knife. Commonly found in riverbeds and gravel pits.