Moss Agate
Chalcedony (cryptocrystalline Quartz) with Chlorite or Hornblende inclusions · Semi-Precious Gemstone / Decorative Stone
Crystal System
Trigonal symmetry on a microscopic scale; typically occurs in massive, botryoidal, or tumbled forms.
Mineral Group
Silicates (Subgroup: Tectosilicates)
Chemical Formula
SiO2 (Silicon Dioxide) with impurities of Fe, Mg, or Al
Formation Process
Found in hydrothermal environments where silica-rich fluids permeate cavities in volcanic rocks (basalts). The green 'moss' forms from the oxidation of minerals like manganese or iron during crystallization.
About This Crystal
A translucent to semi-opaque white or colorless chalcedony containing dark green, branch-like (dendritic) inclusions. This specific tumbled stone shows a dense green pattern with patches of bluish-white translucency and a vitreous to waxy luster.
Physical Characteristics
Color: Green and white/clear; Streak: White; Cleavage: None; Fracture: Conchoidal; Specific Gravity: 2.58–2.64; Luster: Vitreous; Toughness: Very good.
Optical Properties
Refractive Index: 1.530–1.540; Birefringence: Weak (up to 0.004); Pleochroism: None; Optical character: Aggregate (doubly refractive).
Hardness & Durability
Origin Region
India, Brazil, USA (Montana), Uruguay, and Central Europe.
Hardness & Durability
Mohs hardness of 6.5 to 7. Excellent durability and stability, making it ideal for daily jewelry wear such as rings or pendants.
Care & Maintenance
Wash with warm soapy water and a soft brush. While stable, it should avoid extreme heat and harsh acids. Safe for ultrasonic cleaners though manual cleaning is preferred for specimens with surface-reaching pits.
Rarity & Value
Common; widely available. Value is determined by the complexity and beauty of the 'scenic' inclusions. Typically inexpensive, ranging from $1 to $20 for standard tumbled pieces.
Special Characteristics
Dendritic/Arborescent inclusions that resemble moss, trees, or plants. Some specimens may show slight fluorescence under UV light due to trace organics or minerals.
Lore & History
Historically known as the 'Gardener's Stone' in various cultures, believed to ensure a bountiful harvest. In modern crystal healing, it is associated with the Heart Chakra, symbolizing growth, abundance, and a connection to nature.