mineral

Moss Agate

Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxides

Hardness: 6.5–7 on Mohs scale. Color: Clear to milky white chalcedony with green, black, or brown dendritic inclusions. Luster: Vitreous to waxy. Structure: Cryptocrystalline (Trigonal). Cleavage: None (conchoidal fracture). Specific Gravity: 2.58–2.64.

Hardness: 6
Luster: Vitreous to waxy

Identified March 24, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the deposition of silica-rich groundwater in volcanic rock cavities or sedimentary fissures. The 'moss' patterns are formed by dendritic growths of manganese or iron minerals that crystallize inside the chalcedony during formation.

Uses & applications

Predominantly used as a gemstone for jewelry (cabochons, beads, and pendants), ornamental carvings, and by crystal collectors for aesthetic value.

Geological facts

Despite its name, Moss Agate contains no organic moss; the patterns are strictly mineral. In ancient times, it was considered a 'gardener's stone' believed to ensure a bountiful harvest. Unlike many agates, it lacks the characteristic concentric banding.

Field identification & locations

Identify in the field by its translucent body paired with dark, branch-like patterns. Common locations include India, Brazil, Uruguay, and the United States (Montana/Wyoming). Collectors should look for high translucency and distinct, vibrant 'forest-like' patterns.

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