sedimentary

Chert (Jasper)

Microcrystalline Quartz (SiO2)

AI-generated identification · may be incorrect

Hardness: 6.5-7 (Mohs scale); Color: Brownish-red to earthy orange; Luster: Waxy to dull; Crystal structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific gravity: 2.6-2.7

Hardness: 6
Color: Brownish-red to earthy orange
Luster: Waxy to dull

Identified April 6, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the accumulation of silica-rich organic remains (like radiolaria or diatoms) or chemical precipitation from groundwater. This specimen shows oxidation from iron impurities.

Uses & applications

Historically used for stone tools and arrowheads; currently used in jewelry (as jasper), landscaping, and as a collector specimen.

Geological facts

Jasper has been used throughout human history; it was a favorite gem in the ancient world, mentioned in the Bible and used extensively in Minoan Crete for seals.

Field identification & locations

Identify in the field by its hardness (it will scratch glass), waxy luster, and conchoidal (shell-like) fracture patterns. Found globally in sedimentary bedding.