sedimentary
Dendritic Agate
Silicon Dioxide with Manganese or Iron Oxide inclusions (SiO2)
Hardness: 6.5-7 on Mohs scale; Color: Translucent white or grey with black/brown branch-like inclusions; Luster: Waxy to Vitreous; Crystal Structure: Trigonal (microcrystalline); Cleavage: None; Specific Gravity: 2.58-2.64
- Hardness
- 6
- Luster
- Waxy to Vitreous
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Physical properties
Hardness: 6.5-7 on Mohs scale; Color: Translucent white or grey with black/brown branch-like inclusions; Luster: Waxy to Vitreous; Crystal Structure: Trigonal (microcrystalline); Cleavage: None; Specific Gravity: 2.58-2.64
Formation & geological history
Formed when mineral-rich water, containing manganese or iron, seeps into the fractures or cavities of white/grey agate, depositing minerals in tree-like patterns known as dendrites. These processes occur over millions of years.
Uses & applications
Primarily used in jewelry as cabochons, beads, or pendants. Also popular as a collector's specimen and in metaphysical practices.
Geological facts
Despite its name, dendritic agate is not technically a true banded agate because it lacks the classic concentric banding. The 'dendrites' are not plant fossils, but rather inorganic mineral patterns resembling trees or ferns.
Field identification & locations
Identify by looking for translucent chalcedony hosting distinct, branching 'moss-like' or 'tree-like' dark inclusions. Common in Brazil, India, Madagascar, and the USA. Collectors look for high contrast and artistic patterns.
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