Igneous/Sedimentary (debated)
Kambaba Jasper
Rhyolite (Volcanic rock) or Stromatolite (debated)
Hardness: 6.5-7, Color: Dark green to black with lighter green or yellowish circular/oval spots, Luster: Vitreous to dull, Crystal structure: Microcrystalline quartz, Cleavage: None
- Hardness
- 6
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Physical properties
Hardness: 6.5-7, Color: Dark green to black with lighter green or yellowish circular/oval spots, Luster: Vitreous to dull, Crystal structure: Microcrystalline quartz, Cleavage: None
Formation & geological history
Formed in Madagascar. Origin is debated; traditionally thought to be a fossilized stromatolite (sedimentary), but recent studies suggest it's a rhyolitic volcanic rock (igneous) with orbicular features formed by cooling magma.
Uses & applications
Used primarily in lapidary arts, jewelry, carvings, and as a decorative stone.
Geological facts
Often sold as a fossil (stromatolite) containing ancient cyanobacteria, but petrographic analysis often points to a volcanic origin (rhyolite).
Field identification & locations
Identifiable by its distinct dark green/black background with lighter green orbicular patterns. Found mainly in Madagascar.
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