Rock Identifier
Ocean Jasper (Orbicular Jasper / Variolitic Chalcedony (SiO2)) — mineral
mineral

Ocean Jasper

Orbicular Jasper / Variolitic Chalcedony (SiO2)

Hardness: 6.5-7 on the Mohs scale. Color: Mottled green, teal, brown, and yellowish-cream with distinctive orbicular circular patterns and inclusions. Luster: Dull to waxy when raw, vitreous to silky when polished. Cleavage: None (conchoidal fracture).

Hardness
6
Luster
Dull to waxy when raw, vitreous to silky when polished
Identified More mineral
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Physical properties

Hardness: 6.5-7 on the Mohs scale. Color: Mottled green, teal, brown, and yellowish-cream with distinctive orbicular circular patterns and inclusions. Luster: Dull to waxy when raw, vitreous to silky when polished. Cleavage: None (conchoidal fracture).

Formation & geological history

Forms in silicified rhyolite or tuff flows where silica-rich fluids deposit microcrystalline quartz and chalcedony around nucleation points, forming orb-like sphere patterns during low-temperature hydrothermal activity.

Uses & applications

Widely used as an ornamental gemstone, for lapidary arts, cabochons, carved figurines, tumbled stones, and popular among rock collectors.

Geological facts

Ocean Jasper is a famous trade name for a rare orbicular chalcedony found exclusively along the remote northwest coast of Madagascar, originally collected near Marovato.

Field identification & locations

Identified by its distinctive rounded, eye-like orbicular pattern (spheres) embedded within a microcrystalline chalcedony or jasper matrix. Found primarily along tidal zones in Madagascar.