mineral

Polished ocean jasper (likely orbicular jasper)

Microcrystalline quartz (chalcedony), SiO₂, with iron oxides and other silicates

AI-generated identification · may be incorrect

Opaque to slightly translucent, brown-red, olive, cream, and blue-green coloration with polished vitreous-to-waxy luster; hardness about 6.5–7 Mohs, no cleavage, and cryptocrystalline structure. The rounded shape and glossy surface indicate human polishing.

Identified August 23, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich fluids fill cavities or replace volcanic rock, commonly producing orbicular patterns; most ocean jasper comes from Eocene–Miocene volcanic terrains of Madagascar. Exact identification and age require testing or provenance.

Uses & applications

Used for cabochons, carvings, tumbled stones, and ornamental objects; it is generally a decorative lapidary material rather than an industrial stone.

Geological facts

“Ocean jasper” is a trade name, not a single formally defined mineral species. True orbicular material shows concentric spheres or eyes, while this piece appears brecciated or mottled and may also be another jasper or chalcedony variety.

Field identification & locations

Check for very fine quartz texture, glassy/waxy polish, opaque coloration, and resistance to scratching by a steel blade; quartz will scratch glass but should not be identified by destructive tests on valuable pieces. Common sources include Madagascar, Mexico, Indonesia, and the western United States.