mineral

Polished ocean jasper

Jasper, microcrystalline quartz (SiO₂), commonly with iron oxides and chlorite/minor accessory minerals

AI-generated identification · may be incorrect

A polished, opaque chalcedonic quartz aggregate with mottled green, red, brown, and cream patterns; Mohs hardness 6.5–7, vitreous to waxy luster, no visible cleavage, and typical specific gravity around 2.6. The rounded shape indicates tumbling or cabochon-style polishing.

Identified August 19, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich fluids replace or cement volcanic rocks, with iron and other minerals producing the colorful orbicular patterns. Most commercial ocean jasper comes from Miocene–Oligocene volcanic rocks near Madagascar, though “jasper” is also found worldwide.

Uses & applications

Used for cabochons, beads, carvings, tumbled stones, and ornamental objects; it is valued primarily as a decorative gemstone rather than an industrial material.

Geological facts

Ocean jasper is famous for concentric or orbicular patterns, though this specimen appears more brecciated or mottled than strongly orbicular. Pattern, polish, color contrast, and locality determine desirability.

Field identification & locations

Identify it by its opaque coloration, fine-grained texture, lack of cleavage, and ability to scratch glass; unlike glass, it usually shows earthy internal patterning. Common sources include Madagascar, Oregon, Brazil, India, and Australia.