sedimentary
Orbicular Jasper (Ocean Jasper variant)
Silicon Dioxide (SiO2) with iron oxide inclusions
Hardness: 6.5-7 (Mohs scale); Color: Red base with circular 'orb' inclusions; Luster: Dull to vitreous; Crystal Structure: Hexagonal (cryptocrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.6-2.8
- Hardness
- 6
- Color
- Red base with circular 'orb' inclusions
- Luster
- Dull to vitreous
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Physical properties
Hardness: 6.5-7 (Mohs scale); Color: Red base with circular 'orb' inclusions; Luster: Dull to vitreous; Crystal Structure: Hexagonal (cryptocrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.6-2.8
Formation & geological history
Formed through the precipitation of silica in volcanic or sedimentary environments where the circular 'orbs' develop as spherulitic structures during mineral growth. Usually associated with hydrothermal activity.
Uses & applications
Primarily used for lapidary work, jewelry (cabochons), and as a decorative collector specimen.
Geological facts
The circular eye-like patterns are actually three-dimensional spheres called spherulites. While jasper is common, specific 'orbicular' patterns are relatively rare compared to solid jasper.
Field identification & locations
Identify in the field by its distinct circular patterns (eyes), extreme hardness (it will scratch glass), and waxy feel when polished. Common in volcanic regions with high silica content.
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