mineral

Polished ocean jasper

Orbicular jasper (microcrystalline quartz, SiO₂)

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; opaque, multicolored red, green, cream, gray, and lavender patterns; waxy to vitreous luster; cryptocrystalline quartz with no visible cleavage. The rounded specimen is polished and likely tumbled or cabochon-cut.

Identified September 17, 2026More mineral →

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Physical properties

Formation & geological history

A silica-rich volcanic rock formed when chalcedony and quartz replaced or filled cavities in altered rhyolitic lava, commonly producing orbicular patterns. Classic ocean jasper formed mainly in Oligocene–Miocene volcanic rocks of Madagascar, roughly 5–30 million years old.

Uses & applications

Used for cabochons, beads, carvings, polished display stones, and metaphysical collectibles; it is not generally used as structural stone.

Geological facts

“Ocean jasper” is a trade name, and true material historically came from coastal Madagascar deposits accessible only at low tide. Patterns vary dramatically, making individual pieces distinctive.

Field identification & locations

Identify it by its opaque multicolor brecciated or orbicular patterns, quartz-like hardness, and inability to scratch with steel easily; acid causes no fizz. Common sources include Madagascar, Australia, Mexico, and the western United States.