sedimentary
Ocean Jasper
Orbicular Jasper (Silicon Dioxide SiO2)
Hardness: 6.5-7 Mohs; Color: Varied greens, browns, and grays with orbicular (circular) patterns; Luster: Vitreous to waxy; Crystal Structure: Trigonal/Microcrystalline; Cleavage: None; Specific Gravity: 2.58-2.91.
- Hardness
- 6
- Luster
- Vitreous to waxy
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Physical properties
Hardness: 6.5-7 Mohs; Color: Varied greens, browns, and grays with orbicular (circular) patterns; Luster: Vitreous to waxy; Crystal Structure: Trigonal/Microcrystalline; Cleavage: None; Specific Gravity: 2.58-2.91.
Formation & geological history
Ocean Jasper is a silicified rhyolite or tuff that formed from volcanic activity where silica-rich fluids precipitated in rhythmic layers, creating orbicular patterns. It is found exclusively in the Marovato region of Madagascar.
Uses & applications
Primarily used for ornamental purposes, lapidary art, jewelry, and as a popular specimen for crystal collectors.
Geological facts
This specific variety is only found at low tide along the coast of Madagascar. The original deposits are largely depleted, making high-quality older material more rare and valuable.
Field identification & locations
Identify by the unique 'eye' or flower-like orbicular patterns and high silica content. Collectors look for vibrant color contrast and well-defined circles within the stone.
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