mineral

Moss Agate

Silicon Dioxide (SiO2) with inclusions

AI-generated identification · may be incorrect

Hardness: 6.5-7.0 (Mohs). Color: Translucent gray/white with dark green or black moss-like inclusions. Luster: Vitreous to waxy. Crystal system: Trigonal/Microcrystalline. Specific gravity: 2.58-2.64.

Hardness: 6
Luster: Vitreous to waxy

Identified July 1, 2026More mineral →

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Physical properties

Formation & geological history

Formed as a result of weather volcanic rocks. It develops in volcanic cavities when mineral-rich water seeps through and deposits silica along with iron or manganese oxides which form the dendritic inclusions.

Uses & applications

Primarily used in jewelry (cabochons, beads), decorative carvings, and as a popular collector's specimen. Historically used in talismans.

Geological facts

Despite the name, moss agate does not contain organic matter; the 'moss' is actually dendritic inclusions of manganese or iron oxides. It is often associated with the 'gardener's stone' folklore.

Field identification & locations

Identify by its characteristic branching tree-like or moss-like green patterns suspended in translucent chalcedony. It can be found globally with significant deposits in India, Brazil, and the USA (Montana/Oregon).