mineral

Polished ocean jasper (orbicular jasper)

Microcrystalline quartz/chalcedony (SiO₂) with iron oxides and assorted alteration minerals

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; glassy to waxy luster; cream, orange-red, gray, and brown coloring with rounded orbicular patterns. Massive, cryptocrystalline structure with no cleavage; specific gravity approximately 2.5–2.7.

Identified August 11, 2026More mineral →

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Physical properties

Formation & geological history

Forms from silica-rich volcanic fluids that fill cavities and fractures, with concentric mineral growth and iron staining; most classic material is Oligocene–Miocene volcanic rock from Madagascar. The shown piece is polished and likely tumbled.

Uses & applications

Used for cabochons, beads, carvings, lapidary pieces, and mineral collections; occasionally used decoratively. Value depends on pattern, polish, translucency, and provenance.

Geological facts

Ocean jasper is a trade name rather than a single precisely defined mineral species; orbicular patterns may include chalcedony, quartz, feldspar, and iron oxides.

Field identification & locations

Identify by its opaque-to-translucent chalcedony body, rounded colorful orbs, waxy/glassy polish, and lack of obvious cleavage. Common sources include Madagascar, Mexico, and Australia.