sedimentary

Ocean Jasper

Orbicular Jasper (Silicon Dioxide, SiO2)

Hardness: 6.5-7 (Mohs scale); Color: Multicolored with greens, browns, and oranges; Luster: Vitreous to waxy when polished; Crystal structure: Hexagonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific gravity: 2.58-2.91

Hardness: 6
Color: Multicolored with greens, browns, and oranges
Luster: Vitreous to waxy when polished

Identified April 28, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed as a rhyolitic or sedimentary deposit where silica-rich fluids cooled and crystallized in spherical patterns (orbicular) within volcanic or sedimentary layers. Most famous deposits are from the Cretaceous period.

Uses & applications

Mainly used for ornamental carvings, jewelry (cabochons), and as a popular semi-precious stone for metaphysical collectors.

Geological facts

This specific variety is famously found along the coast of Madagascar and can only be harvested at low tide by boat. It is technically a variety of chalcedony containing iron oxides and other mineral inclusions that create its unique patterns.

Field identification & locations

Identify by its characteristic 'ocean' colors (greens and blues) and orb-like circular patterns or 'eyes.' It is often found as water-worn pebbles in coastal regions or riverbeds near volcanic activity.

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