Mineral

Moss Agate

Chalcedony (Silicon Dioxide - SiO2) with inclusions

Hardness: 6.5-7 (Mohs scale); Color: Clear to milky white with green, dendritic inclusions; Luster: Vitreous to waxy; Crystal Structure: Trigonal (cryptocrystalline); Cleavage: None; Specific Gravity: 2.58-2.64.

Hardness: 6
Color: Clear to milky white with green, dendritic inclusions
Luster: Vitreous to waxy

Identified April 4, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the deposition of silica in fissures or cavities of volcanic rocks. The 'moss' patterns are created by manganese or iron oxide inclusions that crystallize in dendritic patterns during mineral formation.

Uses & applications

Primarily used in jewelry making (beads, cabochons), ornamental carvings, and as a popular specimen for metaphysical gemstone collectors.

Geological facts

Despite its name, moss agate is not an organic material and contains no actual moss. It is sometimes called the 'Mocha Stone' after the Arabian city of Mocha, which was once a source of the stone.

Field identification & locations

Identify in the field by its characteristic green branching inclusions within semi-translucent chalcedony. It lacks the concentric banding found in 'true' agates. Commonly found in India, Brazil, Uruguay, and the United States (Montana).

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