mineral

Moss Agate

Cryptocrystalline Quartz (SiO2 with Manganese or Iron Oxide inclusions)

Hardness: 6.5-7 on Mohs scale; Color: Translucent white or gray with green, brown, or red dendritic inclusions; Luster: Vitreous to waxy; Crystal Structure: Trigonal/Microcrystalline; Cleavage: None; Specific Gravity: 2.58-2.64

Hardness: 6
Luster: Vitreous to waxy

Identified May 20, 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 'moss' patterns are formed by the presence of manganese and iron oxides during the crystallization process. It can be found in volcanic regions of all geological ages.

Uses & applications

Primary use is in jewelry (cabochons, beads, pendants), ornamental carvings, and as a popular specimen for gemstone collectors.

Geological facts

Despite its name, moss agate does not contain organic matter; the plant-like moss patterns are actually inorganic mineral dendrites. In ancient times, it was believed to be a stone of agriculture that helped crops grow.

Field identification & locations

Identify by its translucent body combined with branching, moss-like inclusions. Commonly found in India, Brazil, Uruguay, and the western United States. It is often found in riverbeds as water-worn pebbles.

Other mineral specimens

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Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Schist

Metamorphic

Epidote

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metamorphic

Nephrite Jade

Nephrite

Mineral/Rock

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety often found as a river rock)

Metamorphic Rock

Green Apatite on Albite

Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]

mineral