mineral

Tree Agate (or Moss Agate)

Dendritic Agate (Silicon Dioxide - SiO2)

Hardness: 6.5-7 (Mohs scale); Color: White to milky clear with green branching patterns; Luster: Vitreous to waxy; Crystal structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific gravity: 2.58-2.64.

Hardness: 6
Color: White to milky clear with green branching patterns
Luster: Vitreous to waxy

Identified March 22, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the infiltration of manganese or iron oxides into cracks within quartz or chalcedony. The 'moss' or 'tree' patterns are dendritic inclusions that grow as the mineral cools or crystallizes in volcanic rock cavities (vugs). Most specimens are from the Cenozoic era.

Uses & applications

Primarily used for jewelry (cabochons, beads), decorative carvings, meditation stones, and as a popular specimen for mineral collectors due to its unique botanical patterns.

Geological facts

Despite its name, Moss or Tree Agate contains no organic plant material; the green patterns are strictly metallic mineral inclusions. It was historically prized by farmers in various cultures as a 'talisman' for a successful harvest.

Field identification & locations

Identify in the field by its distinctive green 'fern-like' patterns against a white chalcedony base and its high hardness (it will scratch glass). Common locations include India, Brazil, the US (Montana and Wyoming), and Uruguay.

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