Tree Agate
Quartz (Variety: Chalcedony) with Dendritic Inclusions · Semi-Precious Gemstone
Crystal System
Trigonal/Microcrystalline; massive habit with no visible external crystal faces
Mineral Group
Silicates (Tectosilicate)
Chemical Formula
SiO2 (Silicon Dioxide) with impurities of Chlorite or Manganese/Iron oxides
Formation Process
Hydrothermal formation where silica-rich fluids fill cavities in volcanic rock, with dendritic mineral inclusions forming as the silica solidifies.
About This Crystal
A white to grayish translucent chalcedony featuring moss-like or tree-like green inclusions. It has a vitreous to waxy luster and is typically seen in polished or tumbled forms.
Physical Characteristics
Color: White with green patterns. Streak: White. Cleavage: None. Fracture: Conchoidal. Specific Gravity: 2.58 - 2.64. Tenacity: Brittle but tough.
Optical Properties
Refractive Index: 1.530 - 1.543. Birefringence: Up to 0.004. Optical Character: Uniaxial positive. Phenonema: None.
Hardness & Durability
Origin Region
Brazil, India, Uruguay, and USA (Montana). Found in volcanic cavities and sedimentary environments.
Hardness & Durability
Mohs Hardness: 6.5 to 7. Excellent durability for jewelry and daily wear; resistant to scratching.
Care & Maintenance
Clean with warm soapy water and a soft brush. Avoid harsh chemicals and ultrasonic cleaners if the stone has surface-reaching fractures.
Rarity & Value
Common. Generally inexpensive, valued based on the complexity and aesthetic appeal of the 'dendritic' patterns.
Special Characteristics
Features dendritic or arborescent inclusions that resemble botanical life, created by branching mineral oxides.
Lore & History
Historically used in agriculture to ensure a good harvest. Symbolically associated with stability, growth, and a connection to the natural world.