Ocean Jasper

Physical Properties

Hardness: 6.5-7 (Mohs scale); Color: Multicolored with circular pattern; Luster: Vitreous to waxy; Crystal Structure: Trigonal (Microcrystalline); Cleavage: None; Specific Gravity: 2.58-2.91

Formation & Geological History

Formed through the precipitation of silica in volcanic flows (rhyolite), typically containing circular structures called spherulites. Many specimens are found in deposits that are only reachable at low tide.

Uses & Applications

Primarily used for ornamental purposes, lapidary arts, jewelry (cabochons), and collection by mineral enthusiasts.

Geological Facts

Ocean Jasper is specifically found along the coast of Madagascar. The name refers to the fact that the original deposits were located in the intertidal zone, making mining possible only during low tide.

Field Identification & Locations

Identify by its distinctive 'orbicular' (circular/eye-like) patterns and range of earthy tones. It can be found in the Marovato region of Madagascar. Collectors look for high contrast in the 'eyes' and lack of pitting.

Identified on: 4/22/2026

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