Green Tourmaline
Elbaite var. Green Tourmaline · Semi-Precious Gemstone
Crystal System
Trigonal system, typically forming prismatic crystals with vertical striations, often occurring here as tumbled or partially polished baroque bead shapes.
Mineral Group
Silicates, specifically the Cyclosilicate subgroup
Chemical Formula
Na(Li1.5Al1.5)Al6(Si6O18)(BO3)3(OH)4
Formation Process
Pegmatitic and hydrothermal formation, crystallizing from cooling magmatic fluids rich in water, boron, lithium, and other volatile elements at moderate to high temperatures.
About This Crystal
The specimen consists of multiple drilled baroque-style tumbled beads featuring shades of pale to medium forest green, with translucent to opaque transparency, vitreous to waxy luster, and visible dark inclusions and natural surface imperfections.
Physical Characteristics
Color ranges from olive to vibrant green with a white streak; brittle tenacity with uneven to conchoidal fracture and distinct conchoidal breakage patterns; specific gravity ranges from 3.00 to 3.25; no notable cleavage.
Optical Properties
Uniaxial negative with strong dichroism, showing different shades of green or yellowish-green depending on the viewing angle; double refraction with a birefringence of approximately 0.018 to 0.040.
Hardness & Durability
Origin Region
Found globally with notable sources in Brazil, Madagascar, Afghanistan, Nigeria, and the USA (California and Maine); typically forms in pegmatites and hydrothermal veins.
Hardness & Durability
Mohs hardness of 7 to 7.5, making it quite durable and suitable for everyday jewelry wear, though its brittle nature requires care against sharp impacts.
Care & Maintenance
Clean with warm soapy water and a soft brush; avoid ultrasonic or steam cleaners due to internal fractures and inclusions; store separately to prevent scratching softer stones.
Rarity & Value
Common to moderately rare depending on clarity and color saturation; lower-grade tumbled beads are generally affordable, while high-clarity gem-grade material commands significantly higher prices.
Special Characteristics
Strong pleochroism and vertical striations on raw crystal surfaces; piezoelectric and pyroelectric properties, allowing the crystal to generate an electrical charge when heated or subjected to pressure.
Lore & History
Historically associated with vitality, strength, and courage, green tourmaline is traditionally linked to the heart chakra in metaphysical practices, believed to promote compassion, healing, and abundance.