mineral

Moss Agate

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

Hardness: 6.5-7 (Mohs scale), Color: Clear/white chalcedony with dark green, moss-like inclusions, Luster: Vitreous to waxy, Crystal Structure: Trigonal (cryptocrystalline), Cleavage: None, SG: 2.58-2.64

Hardness: 6

Identified July 2, 2026More mineral →

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Physical properties

Formation & geological history

Formed from the weathering of volcanic igneous rocks where silicate-rich water deposits cryptocrystalline quartz in cavities. The 'moss' consists of dendritic inclusions of metal oxides.

Uses & applications

Primarily used in jewelry, lapidary arts (cabochons), and as a collector's specimen due to its unique patterns.

Geological facts

Despite its name, moss agate does not contain organic matter. The green patterns are inorganic mineral growths that mimic plant life. It has been used as a talisman for centuries, often associated with agriculture and gardeners.

Field identification & locations

Identify by its characteristic 'branched' or mossy green inclusions within a translucent or white matrix. Frequently found in India, Brazil, Uruguay, and the western United States (Montana).

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Metamorphic

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Gypsum (variety Selenite or Alabaster)

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Mineral

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Nephrite

Mineral/Rock

Granite

Granite (Phaneritic intrusive igneous rock)

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