mineral

Polished Ocean Jasper (orbicular jasper)

Microcrystalline quartz (SiO₂), with iron oxides and other alteration minerals

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; opaque mustard-yellow, brown, black, and green coloration with irregular orbicular/brecciated patterns; vitreous to waxy luster and no visible cleavage. Specific gravity is approximately 2.6.

Identified August 30, 2026More mineral →

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Physical properties

Formation & geological history

A silica-rich volcanic rock later replaced and filled by chalcedony and quartz, with iron- and manganese-bearing minerals producing the dark patterns. Most classic material formed in Oligocene–Miocene volcanic rocks of Madagascar, roughly 5–30 million years old.

Uses & applications

Commonly cut and polished into cabochons, worry stones, beads, carvings, and decorative objects; it has limited industrial use. Attractive patterning gives it moderate collector and lapidary value.

Geological facts

Despite the trade name “Ocean Jasper,” it is jasper rather than a distinct mineral species. Orbicular patterns may resemble eyes, blooms, or landscape scenes.

Field identification & locations

Identify it by its opaque, fine-grained silica body, strong polish, and colored orbicular or brecciated pattern; it should not show glassy translucence or easy cleavage. Comparable jasper occurs worldwide, while ocean-side orbicular material is especially associated with Madagascar.