mineral

Tumbled ocean jasper / orbicular jasper (probable)

Microcrystalline quartz (SiO₂) with hematite, feldspar, and other inclusions

AI-generated identification · may be incorrect

Polished, rounded pebble with mottled gray, brown, reddish, and cream patches; vitreous to waxy luster and no visible cleavage. Quartz-rich jasper is typically Mohs 6.5–7, with specific gravity about 2.6; exact identification is limited by the photograph.

Identified August 31, 2026More mineral →

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Physical properties

Formation & geological history

Jasper forms when silica-rich fluids replace or cement volcanic and sedimentary material; orbicular varieties develop concentric mineral growth patterns. Most commercial ocean jasper comes from Miocene volcanic rocks near Madagascar, roughly 5–23 million years old.

Uses & applications

Used for cabochons, beads, carvings, tumbled stones, and ornamental objects; common polished pieces generally have modest value.

Geological facts

Red and brown colors commonly reflect iron oxides, while gray areas are silica-rich chalcedony or jasper. “Ocean jasper” is a trade name rather than a single formally defined mineral species.

Field identification & locations

Look for opacity, fine grain, hardness sufficient to scratch glass, and iron-colored patterns; jasper lacks the translucency typical of agate. Common sources include Madagascar, India, Brazil, and the western United States.