mineral

Polished ocean jasper

Orbicular jasper (microcrystalline quartz, SiO₂)

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; opaque brown, cream, and white orbicular pattern with a glassy-to-waxy polish. It is cryptocrystalline quartz with no visible cleavage and typically specific gravity near 2.6.

Identified September 15, 2026More mineral →

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Physical properties

Formation & geological history

A variety of jasper formed when silica-rich fluids filled cavities and replaced volcanic rock, producing spherical mineral growths. Classic material comes from Oligocene–Miocene volcanic rocks of Madagascar, roughly 5–30 million years old.

Uses & applications

Used for cabochons, beads, carvings, worry stones, and decorative objects; its value is primarily ornamental and collectible rather than industrial.

Geological facts

The trade name “ocean jasper” is commonly applied to orbicular jasper from Madagascar, although not all orbicular jasper originates there. The concentric or cloudlike “orbs” reflect repeated silica and mineral deposition.

Field identification & locations

Identify it by its opaque orbicular pattern, fine-grained texture, and inability to scratch with a steel knife; quartz should scratch ordinary glass. Common sources include Madagascar, Mexico, Indonesia, and Oregon.