sedimentary
Jasper with Dendritic Inclusions
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Hardness: 6.5-7 on Mohs scale; Color: Yellow-brown (limonite staining) with white and black patterns; Luster: Dull to waxy; Structure: Cryptocrystalline; Cleavage: None (conchoidal fracture).
- Hardness
- 6
- Luster
- Dull to waxy
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Physical properties
Hardness: 6.5-7 on Mohs scale; Color: Yellow-brown (limonite staining) with white and black patterns; Luster: Dull to waxy; Structure: Cryptocrystalline; Cleavage: None (conchoidal fracture).
Formation & geological history
Formed through the accumulation of silica-rich fluids in volcanic cavities or sedimentary layers. The black 'tree-like' patterns (dendrites) are manganese oxide inclusions that crystallized as the silica solidified into stone.
Uses & applications
Commonly used for lapidary work, cabochons, jewelry making, and as a decorative river stone or collector's specimen.
Geological facts
The term 'dendrite' comes from the Greek word 'dendron' meaning tree. Though they look like fossils of ferns or plants, they are purely inorganic mineral Growths.
Field identification & locations
Identify in the field by its hardness (it will scratch glass), smooth water-worn surface, and opaque nature. Commonly found in riverbeds and coastal regions across North America and Australia.
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