mineral
Moss Agate
Chalcedony (SiO2) with inclusions of hornblende or chlorite
Hardness: 6.5-7 (Mohs); Color: Translucent white or grayish with green, dendritic inclusions; Luster: Vitreous to waxy; Crystal structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture)
- Hardness
- 6
- Luster
- Vitreous to waxy
Identified More mineral →
Explore Moss Agate in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6.5-7 (Mohs); Color: Translucent white or grayish with green, dendritic inclusions; Luster: Vitreous to waxy; Crystal structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture)
Formation & geological history
Formed through the deposition of silica from groundwater into cavities in volcanic rocks. The 'moss' patterns are caused by chemical impurities such as iron or manganese oxide and chlorite settling during the cooling process.
Uses & applications
Primarily used in jewelry (cabochons), ornamental carvings, and by crystal collectors for its aesthetic patterns.
Geological facts
Despite its name, moss agate does not contain organic matter; the 'moss' is actually mineral inclusions. It was historically prized as a stone of agriculture and prosperity by early gardeners and farmers.
Field identification & locations
Identified by its distinctive plant-like green patterns against a milky translucent background. Found commonly in India, Brazil, the US, and Uruguay. Look for the 'dendritic' growth inside the stone.
More like this
Other mineral specimens
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Schist
Schist
Metamorphic
Sandstone with Mineral Veining or Crust
Sedimentary Sandstone (mostly SiO2 with Fe2O3 tinting)
sedimentary
Potassium Feldspar (Orthoclase)
Orthoclase (KAlSi3O8)
mineral
Gypsum (variety Selenite or Alabaster)
Calcium sulfate dihydrate (CaSO4·2H2O)
Mineral
Nephrite Jade
Nephrite
Mineral/Rock