mineral

Moss Agate

Chalcedony (SiO2 with inclusions)

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

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

Identified July 20, 2026More mineral →

Explore Moss Agate in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

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

Formation & geological history

Formed via the deposition of silica from groundwater in the cavities of igneous rocks. The dendritic moss-like patterns are created by manganese or iron oxides during mineral formation.

Uses & applications

Primarily used in jewelry (pendants, rings), ornamental carvings, and as a popular specimen for collectors.

Geological facts

Despite its name, moss agate does not contain organic matter; the 'moss' is actually mineral inclusions of manganese and iron that grow into branching patterns.

Field identification & locations

Identified by its signature moss-like inclusions against a translucent or milky background. Commonly found in India, Brazil, Uruguay, and the United States (specifically the Yellowstone River area).