Green Tourmaline
Elbaite var. Green Tourmaline · Semi-Precious Gemstone and Mineral Specimen
Crystal System
Trigonal, typically forming prismatic crystals with rounded triangular cross-sections and striations parallel to the c-axis
Mineral Group
Silicates (Cyclosilicates)
Chemical Formula
Na(Al1.5Li0.5)Al6(Si6O18)(BO3)3(OH)4
Formation Process
Pegmatitic and hydrothermal veins, formed during the late stages of magmatic crystallization at high temperatures and pressures
About This Crystal
This specimen is a dark green, blocky crystal fragment with a semi-translucent to opaque appearance, vitreous to resinous luster, and a distinct drilled or natural perforation feature visible on the surface.
Physical Characteristics
Dark green body color, white streak, conchoidal to uneven fracture, poor cleavage, specific gravity of approximately 3.0 to 3.2, and brittle tenacity
Optical Properties
Uniaxial negative with strong dichroism, showing different shades of green depending on the viewing angle; double refraction is strong
Hardness & Durability
Origin Region
Brazil, Madagascar, Afghanistan, Nigeria, USA (California, Maine), and Pakistan
Hardness & Durability
Mohs hardness of 7 to 7.5, good durability for everyday jewelry wear although internal fractures can create points of weakness
Care & Maintenance
Clean with warm soapy water and a soft brush; avoid ultrasonic and steam cleaners due to internal inclusions and fractures; store separately to prevent scratching softer stones
Rarity & Value
Common to uncommon depending on clarity and color saturation; higher grade gem-quality material commands significant value, while crystal specimens and carved beads are moderately priced
Special Characteristics
Strong pleochroism and vertical striations along the crystal prism faces; often exhibits pyroelectricity and piezoelectricity
Lore & History
Historically used as an amulet for protection and healing; associated with the heart chakra in modern crystal healing traditions to promote compassion, healing, and emotional balance