sedimentary
Ocean Jasper
Silicon Dioxide (SiO2) with various inclusions
Hardness: 6.5-7 (Mohs scale), Color: Green with dark veins and patches, Luster: Vitreous to waxy, Crystal Structure: Microcrystalline (trigonal), Cleavage: None/Conchoidal fracture
- Hardness
- 6
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Physical properties
Hardness: 6.5-7 (Mohs scale), Color: Green with dark veins and patches, Luster: Vitreous to waxy, Crystal Structure: Microcrystalline (trigonal), Cleavage: None/Conchoidal fracture
Formation & geological history
Formed as a result of hydrothermal activity and volcanic deposition, usually found in coastal volcanic areas. The circular patterns (orbicules) occur from radial growth of quartz and feldspar fibers.
Uses & applications
Primarily used for ornamental purposes, lapidary art, jewelry (cabochons), and as a collector's specimen due to its unique patterns.
Geological facts
Ocean jasper is unique because it is only found along the coast of Madagascar, specifically in areas accessible only by boat during low tide. The original deposits were depleted and rediscovered multiple times.
Field identification & locations
Identify by its characteristic orbicular (eye-like) patterns and varied colors. Collectors look for high contrast in patterns and lack of surface pitting. It is commonly found on beaches in the Marovato region of Madagascar.
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