mineral

Moss Agate

Silicon Dioxide (SiO2) with inclusions

Hardness: 6.5-7 on Mohs scale; Color: Translucent to opaque white/clear with green hornblende, chlorite, or iron inclusions creating moss-like patterns; Luster: Vitreous to waxy; Crystal structure: Trigonal (microcrystalline/cryptocrystalline quartz); Specific gravity: 2.58-2.64.

Hardness: 6
Luster: Vitreous to waxy

Identified July 27, 2026More mineral →

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Physical properties

Formation & geological history

Formed within volcanic rock cavities (geodes) or weathered limestone through hydrothermal deposition of silica-rich solutions containing manganese and iron oxides.

Uses & applications

Used extensively in jewelry (cabochons, beads, rings), lapidary arts, decorative carvings, and as a popular tumbled stone for rock collectors.

Geological facts

Despite its name, moss agate does not contain any organic moss or plant material. The intricate green, black, or brown branch-like patterns inside are dendrites formed by mineral impurities like chlorite or iron oxides.

Field identification & locations

Identified by its distinctive green, forest-like or mossy inclusions floating within translucent chalcedony quartz. Commonly found in India, Brazil, Uruguay, Russia, and parts of the United States like Montana.