mineral

Polished ocean jasper (orbicular jasper)

Microcrystalline quartz/chalcedony with iron- and manganese-bearing inclusions; SiO₂

AI-generated identification · may be incorrect

Typically green with darker circular orbicules and a waxy to vitreous luster; Mohs hardness 6.5–7, no cleavage, conchoidal fracture, and specific gravity about 2.6. The rounded shape indicates tumbling or polishing.

Identified August 26, 2026More mineral →

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Physical properties

Formation & geological history

A silica-rich volcanic rock formed when chalcedony and quartz filled cavities or replaced material in ancient volcanic flows, commonly with orbicular mineral growth. Famous material comes from Madagascar and is generally Paleozoic to Mesozoic in age.

Uses & applications

Used for cabochons, beads, carvings, worry stones, and decorative objects; polished pieces are primarily collectible rather than industrial.

Geological facts

Orbicular patterns are concentric mineral-growth textures, not fossils. Green coloration may result from chlorite, celadonite, or other inclusions.

Field identification & locations

Identify it by its opaque, patterned body, waxy polish, lack of cleavage, and inability to scratch glass easily unless an edge is tested. Common localities include Madagascar, Oregon, Mexico, and Australia.