Tourmaline
Elbaite var. Rubellite / Watermelon Tourmaline · Precious and Semi-Precious Gemstone
Crystal System
Trigonal, typically forming prismatic crystals with rounded triangular cross-sections
Mineral Group
Silicates, specifically Cyclosilicates
Chemical Formula
Na(Al1.5Li1.5)Al6(Si6O18)(BO3)3(OH)4
Formation Process
Pegmatitic and hydrothermal veins associated with granitic magmas at high temperatures and pressures
About This Crystal
Small, partly translucent to transparent crystal fragment exhibiting distinct color zoning with a pale pink core and a vibrant, saturated dark pink to red cap or rim, displaying a vitreous luster.
Physical Characteristics
Color ranges from pale pink to dark red; streak is white; cleavage is indistinct; fracture is uneven to subconchoidal; specific gravity is approximately 3.01 to 3.10; tenacity is brittle
Optical Properties
Uniaxial negative with strong dichroism, showing darker colors when viewed parallel to the c-axis and lighter perpendicular to it; doubly refractive with a birefringence of 0.014 to 0.040
Hardness & Durability
Origin Region
Brazil, Madagascar, Afghanistan, Nigeria, USA (California, Maine)
Hardness & Durability
Mohs hardness of 7 to 7.5; fair to good toughness, making it suitable for most jewelry applications though susceptible to thermal shock
Care & Maintenance
Clean with warm soapy water and a soft brush; avoid ultrasonic and steam cleaners as well as sudden temperature changes and harsh chemicals
Rarity & Value
Uncommon to rare depending on clarity, color saturation, and distinct zoning; high-quality bi-color or tri-color tourmalines command significant market value
Special Characteristics
Strong pyroelectric and piezoelectric properties, developing an electrical charge when heated or subjected to mechanical pressure
Lore & History
Associated with the heart chakra, symbolizing compassion, emotional healing, and love; historically used as a talisman for protection and creativity in various cultures