mineral

Moss Agate

Silicon Dioxide with inclusions (SiO2 + impurities)

AI-generated identification · may be incorrect

Hardness: 6.5-7 on Mohs scale; Color: Clear to milky white base with green, dendritic (moss-like) inclusions; Luster: Vitreous to waxy; Crystal Structure: Hexagonal (trigonal microcrystalline); Cleavage: None; Specific Gravity: 2.58–2.64.

Hardness: 6
Luster: Vitreous to waxy

Identified July 20, 2026More mineral →

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Physical properties

Formation & geological history

Formed from the deposition of silica in fissures or cavities of volcanic rocks. The 'moss' structures are actually dendritic inclusions of manganese or iron oxides that form during the cooling process. Common in Cenozoic era volcanic regions.

Uses & applications

Primarily used in jewelry (cabochons, beads), decorative carvings, and as a popular collector's pocket stone or 'worry stone'. Historically used in talismans.

Geological facts

Despite its name, moss agate does not contain organic plant matter. The 'moss' patterns are strictly mineral growths. It was often called the 'gardener's stone' in folklore because it was believed to ensure a good harvest.

Field identification & locations

Identify by its translucent body paired with green organic-looking filigree. Commonly found in India, Brazil, Uruguay, and the western United States (especially Montana). For collectors, look for high transparency in the chalcedony and vibrant, well-defined green patterns.