mineral

Moss Agate

Silicon Dioxide with inclusions (SiO2 + Mn/Fe/Chlorite)

Hardness: 6.5-7 on Mohs scale; Color: Clear or white base with green, brown, or black dendritic inclusions; Luster: Vitreous to waxy; Crystal Structure: Trigonal (microcrystalline); Specific Gravity: 2.58-2.64

Hardness: 6
Luster: Vitreous to waxy

Identified April 4, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the deposition of silica from groundwater into cavities in igneous rocks. The dendritic 'moss' patterns are formed by mineral oxides (manganese or iron) that seeped in during formation.

Uses & applications

Predominantly used for lapidary work, jewelry (cabochons), ornamental carvings (like the tower/obelisk shown), and as a popular specimen for crystal collectors.

Geological facts

Despite its name, Moss Agate does not contain organic matter; the mossy patterns are strictly mineral inclusions. It was historically considered a stone of agriculture and gardeners.

Field identification & locations

Identify in the field by its characteristic branching, moss-like inclusions within a translucent chalcedony. It lacks the concentric banding of 'true' agate but is commercially classified as such.

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