mineral

Polished ocean jasper (orbicular jasper)

Microcrystalline quartz/chalcedony (SiO₂) with iron-oxide and other mineral inclusions

AI-generated identification · may be incorrect

Typically Mohs 6.5–7; this rounded, polished specimen is pale gray-green with cream and yellow-brown orbicular inclusions, vitreous to waxy luster, and no visible cleavage. Its patterns result from fine-grained silica and contrasting mineral spheres or patches.

Identified August 15, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich fluids replace or fill cavities in volcanic rocks, commonly producing orbicular textures; Madagascar is the classic source, with formation generally tied to late Paleozoic–Mesozoic volcanic environments. Exact age and locality cannot be confirmed from the image.

Uses & applications

Used for cabochons, beads, carvings, polished specimens, and decorative objects; it is popular with collectors but usually has modest commercial value.

Geological facts

“Ocean jasper” is a trade name rather than a single formally defined mineral species. The distinctive circular patterns and yellow coloration commonly reflect iron oxides or hydroxides.

Field identification & locations

Identify it by its opaque-to-translucent chalcedony body, polished hardness, and rounded orbicular markings; it should resist scratching by a steel knife. Commonly found in Madagascar, especially coastal deposits, though similar jasper occurs worldwide.