mineral

Polished botryoidal jasper/chalcedony (likely ocean jasper)

Microcrystalline quartz, SiO₂, with iron-oxide and other mineral inclusions

AI-generated identification · may be incorrect

Typically Mohs 6.5–7, brown to honey-brown with purple, cream, yellow, and dark inclusions; vitreous to waxy luster and opaque to slightly translucent. The rounded botryoidal texture and tiny cavities are characteristic, though exact identification cannot be certain from an image.

Identified August 30, 2026More mineral →

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Physical properties

Formation & geological history

Silica-rich fluids filled volcanic cavities and fractures, later depositing chalcedony and jasper with iron and other inclusions; many ocean-jasper specimens formed in Jurassic–Cretaceous volcanic rocks of Madagascar.

Uses & applications

Used as a lapidary stone for cabochons, carvings, polished specimens, and jewelry; valued mainly for attractive patterning rather than industrial use.

Geological facts

“Ocean jasper” is a trade name applied to orbicular or botryoidal jasper, especially material from Madagascar; similar brown material may instead be common jasper, agate, or slag-like chalcedony.

Field identification & locations

Look for a glassy/waxy surface, very fine-grained texture, curved botryoidal bumps, and inability to scratch it with a steel knife; acid testing and provenance help distinguish it from glass or slag. Common sources include Madagascar, Mexico, Indonesia, and Oregon.