mineral

Moss Agate

Silicon Dioxide (SiO2) with Chlorite/Oxide inclusions

Hardness: 6.5-7 (Mohs scale); Color: Green, white, clear, brown; Luster: Vitreous to waxy; Crystal Structure: Hexagonal (trigonal); Cleavage: None; Specific Gravity: 2.58-2.64

Hardness: 6
Color: Green, white, clear, brown
Luster: Vitreous to waxy

Identified May 7, 2026More mineral →

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Physical properties

Hardness: 6.5-7 (Mohs scale); Color: Green, white, clear, brown; Luster: Vitreous to waxy; Crystal Structure: Hexagonal (trigonal); Cleavage: None; Specific Gravity: 2.58-2.64

Formation & geological history

Formed from weathered volcanic rocks where silica-rich groundwater fills cavities and precipitates microcrystalline quartz. Green inclusions are usually manganese or iron oxides, or chlorite minerals.

Uses & applications

Used primarily in lapidary arts for cabochons, carvings, and polished hearts like the specimen shown. Highly valued by collectors and used in decorative jewelry.

Geological facts

Despite its name, moss agate does not contain organic matter; the moss-like patterns are dendritic inclusions formed by metallic minerals during the quartz formation.

Field identification & locations

Identify by its translucent milky quartz base and green dendritic (plant-like) patterns. Commonly found in India, Brazil, Uruguay, and the United States (Montana/Oregon).

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