sedimentary

Polished/patinated jasper slab

Microcrystalline quartz (SiO₂), commonly chalcedony with iron-oxide and clay inclusions

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; opaque brown, tan, cream, and reddish tones with intricate swirling patterns and subdued waxy-to-glassy luster. Massive, cryptocrystalline structure with no visible cleavage; specific gravity about 2.5–2.7.

Identified August 8, 2026More sedimentary →

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Physical properties

Formation & geological history

Jasper forms when silica-rich groundwater replaces or cements volcanic ash, sediments, or altered rock, while iron oxides create the colors. Deposits occur in many ages, especially volcanic and hydrothermal terrains; the surface appears polished or naturally weathered.

Uses & applications

Used for ornamental slabs, cabochons, carvings, bookends, and lapidary jewelry; attractive patterned pieces have modest collector value.

Geological facts

The flowing lines may resemble scenic or ocean jasper, but a precise variety cannot be confirmed from one photograph. Jasper is an opaque member of the quartz family rather than a single mineral species.

Field identification & locations

Identify it by its opaque appearance, fine-grained texture, high hardness, and inability to scratch with a steel knife; a streak test is usually white to pale brown. Common sources include India, Madagascar, Australia, Brazil, Mexico, and the western United States.