gemstone

Polished orbicular jasper (likely ocean jasper)

Jasper, a microcrystalline variety of quartz (SiO₂), with iron-oxide and other mineral inclusions

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; brown, cream, and gray orbicular pattern; opaque, waxy to vitreous luster; cryptocrystalline quartz with no visible cleavage. The rounded, polished form is human-processed.

Identified August 20, 2026More gemstone →

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Physical properties

Formation & geological history

Forms when silica-rich fluids replace volcanic or sedimentary material, with contrasting mineral growth producing orbicules; ocean jasper is associated especially with Miocene volcanic rocks of Madagascar. Exact age and locality cannot be confirmed from the image.

Uses & applications

Used for cabochons, beads, carvings, worry stones, and decorative objects; valued primarily for attractive patterning.

Geological facts

Orbicular jasper’s concentric spots may resemble eyes or rosettes and result from radiating mineral growth, commonly involving quartz, feldspar, chalcedony, and iron oxides.

Field identification & locations

Identify by its opaque body, polished surface, circular orbicules, and lack of crystal faces or cleavage; test hardness cautiously because glass can be scratched by quartz-rich jasper. Common sources include Madagascar, Mexico, Australia, and the western United States.