mineral

Moss Agate

Silicon Dioxide (SiO2) with inclusions of manganese or iron oxide

Hardness: 6.5-7 (Mohs scale); Color: Clear to milky white with green, black, or brown moss-like inclusions; Luster: Vitreous to waxy; Crystal structure: Trigonal/Microcrystalline; Cleavage: None (conchoidal fracture); Specific gravity: 2.58-2.64

Hardness: 6
Luster: Vitreous to waxy

Identified March 25, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the weathering of volcanic rocks. The 'moss' patterns are formed by dendritic branching of manganese or iron oxides during the cooling of silica-rich fluids. It occurs worldwide in hydrothermal veins and basaltic cavities.

Uses & applications

Primarily used in jewelry (cabochons, beads), decorative carvings, and as a popular collector's gemstone. It is also used in metaphysical practices as a 'stone of agriculture' and for grounding.

Geological facts

Despite its name, Moss Agate contains no organic matter; the green patterns are strictly mineral growth. It was historically used as a talisman by European farmers to ensure bountiful harvests.

Field identification & locations

Identify in the field by its translucency and characteristic 'vegetation' patterns that do not follow set geometric planes. Common locations include India, Brazil, Uruguay, and the United States (notably Montana and Oregon).

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