sedimentary
Kambaba Jasper
Stromatolite / Fossilized Algae (Rhyolitic structure)
Hardness: 6.5–7 (Mohs scale); Color: Dark green to black base with circular swirling patterns of lighter green; Luster: Vitreous to dull; Crystal structure: Microcrystalline (trigonal); Specific gravity: 2.6–2.7.
- Hardness
- 6
- Luster
- Vitreous to dull
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Physical properties
Hardness: 6.5–7 (Mohs scale); Color: Dark green to black base with circular swirling patterns of lighter green; Luster: Vitreous to dull; Crystal structure: Microcrystalline (trigonal); Specific gravity: 2.6–2.7.
Formation & geological history
Formed approximately 3 billion years ago (Archean Eon). It is a fossilized stromatolite created by the cyanobacteria (blue-green algae) that helped create Earth's oxygen atmosphere, later silicified into jasper through hydrothermal processes.
Uses & applications
Mostly used for ornamental carvings, polished cabochons for jewelry, and as a popular specimen for rock collectors and metaphysical practitioners.
Geological facts
Despite the name 'Jasper', many geologists argue it is technically a fossilized sedimentary stromatolite. It is often confused with Nebula Stone, which has a different mineral composition.
Field identification & locations
Identify by its distinctive 'crocodile-like' or orbicular green-and-black swirling patterns. It is almost exclusively found in the west-central Bongolava region of Madagascar. Collectors should look for high-contrast 'eyes' or circular patterns.
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