sedimentary
Yellow Jasper with Dendritic Inclusions
Silicon Dioxide (SiO2) with Manganese/Iron Oxide inclusions
Hardness: 6.5-7 (Mohs). Color: Pale yellow/tan with black dendritic patterns. Luster: Vitreous to waxy. Crystal Structure: Hexagonal (cryptocrystalline). Cleavage: None (Conchoidal fracture). Specific Gravity: 2.6-2.9.
- Hardness
- 6
- Color
- Pale yellow/tan with black dendritic patterns
- Luster
- Vitreous to waxy
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Physical properties
Hardness: 6.5-7 (Mohs). Color: Pale yellow/tan with black dendritic patterns. Luster: Vitreous to waxy. Crystal Structure: Hexagonal (cryptocrystalline). Cleavage: None (Conchoidal fracture). Specific Gravity: 2.6-2.9.
Formation & geological history
Formed from the deposition of silica-rich fluids in volcanic or sedimentary environments. The dark tree-like patterns (dendrites) are formed by crystals of manganese or iron oxide growing in hairline fractures or between layers.
Uses & applications
Used primarily for lapidary work, jewelry (cabochons), pocket stones, and decorative carvings. It is popular among collectors for its unique patterns.
Geological facts
The term 'dendrite' comes from the Greek word 'dendron' meaning tree. These patterns are often mistaken for fossils or plants, but they are purely inorganic mineral growths.
Field identification & locations
Identify by its waxy luster, smooth water-worn surface, and characteristic branching black patterns. Commonly found in riverbeds or beaches where silica-rich rocks have eroded.
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