Rock Identifier
Moss Agate (Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxide) — mineral
mineral

Moss Agate

Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxide

Hardness: 6.5-7 on Mohs scale; Color: Clear to milky white with green, black, or red moss-like dendritic inclusions; Luster: Vitreous to waxy; Crystal Structure: Trigonal (cryptocrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.64

Hardness
6
Luster
Vitreous to waxy
Identified More mineral →

Identify your own rocks.

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

App StoreGoogle Play

Physical properties

Hardness: 6.5-7 on Mohs scale; Color: Clear to milky white with green, black, or red moss-like dendritic inclusions; Luster: Vitreous to waxy; Crystal Structure: Trigonal (cryptocrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.64

Formation & geological history

Formed through the weathering of volcanic rocks. Silica-rich groundwater percolates through cavities in igneous rocks, depositing layers of chalcedony. The 'moss' patterns are formed by dendritic oxides of manganese or iron trapped within the cooling silica gel.

Uses & applications

Primarily used in jewelry (cabochons, beads, rings), ornamental carvings, and as a popular specimen for rock collectors and metaphysical practitioners.

Geological facts

Despite its name, Moss Agate does not contain organic matter or real moss; the patterns are purely mineral. It has been historically known as the 'Gardener's Stone' and was used in ancient amulets to ensure a bountiful harvest.

Field identification & locations

Identify by its characteristic branching, plant-like inclusions visible through a translucent or white chalcedony base. Commonly found in India, Brazil, Uruguay, and the western United States (Montana). Collectors look for high translucency and high-contrast, well-defined dendritic 'trees'.

More like this

Other mineral specimens

Sandstone (with potential mineral staining/concretions) (Arenite (SiO2 based)) — sedimentary

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary
Epidote (Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)) — metamorphic

Epidote

Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

metamorphic
Nephrite Jade (Nephrite) — Mineral/Rock

Nephrite Jade

Nephrite

Mineral/Rock
Banded Gneiss (River Rock/Pebble) (Gneiss (specifically a banded variety often found as a river rock)) — Metamorphic 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

Green Apatite on Albite

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

mineral
Epidote (Epidote - Ca2(Al2,Fe3+)3(SiO4)3(OH)) — mineral

Epidote

Epidote - Ca2(Al2,Fe3+)3(SiO4)3(OH)

mineral