Elbaite (Tourmaline) Gemstone & Information | Gemopedia by JTV | Gemopedia™

Elbaite (Tourmaline)

The tourmaline family consists of at least 14 distinct minerals, but the variety elbaite accounts for nearly all gem-quality tourmaline. It was named as a result of the colored and colorless tourmalines found on the picturesque island of Elba off the western coast of Italy--history buffs know this island as the place where Napoleon Bonaparte was exiled in 1814. Although best known in shades of green and red, elbaite can also be blue, purple, yellow, or colorless. Notable varieties of elbaite include rubellite, green tourmaline, indicolite, watermelon tourmaline, Paraiba tourmaline and colorless.

Colors

Green, Blue, Red, Orange, Yellow, Colorless

  • Elbaite-tourmaline classification

    CommonName
    Elbaite (Tourmaline)
    Species
    Elbaite
    Variety
    Colors
    Green, Blue, Red, Orange, Yellow, Colorless
    AlternateNames
    GemstoneGroups
    KeySeparations
    appearance, refractive index and high birefringence; then optic figure, pleochroism and specific gravity
    ClassificationComments
    Dark material might have birefringence as high as 0.040Paraba Tourmaline is a Cuprian Elbaite.Rubellite is the red to pink variety.
  • Elbaite-tourmaline chemistry & crystallography

    ChemicalName
    complex boro-silicate of Al, Mg and Fe
    ChemicalFormula
    Na(Li1.5Al1.5)Al6(Si6O18)(BO3)3(OH)3(OH)
    Synthesis
    CrystalSystem
    Trigonal
    ChemistryClassification
    Silicate
    Nature
    Natural
    Crystallinity
    Crystalline
    ChemistryComments
  • Elbaite-tourmaline optical properties

    Transparency
    Transparent - Translucent
    Dispersion
    Strength: moderate fire Value: 0.017
    OpticalComments
    RefractiveIndex
    1.614-1.666
    Birefringence
    0.014-0.032
    OpticCharacter
    Uniaxial
    OpticSign
    Negative
    PolariscopeReaction
    Doubly Refractive (DR)
    Fluorescence
    SWUV: Inert
    LWUV: Inert
    CCFReaction
    Pleochroism
    Dichroic, moderate to strong, varying shades of body color
  • Elbaite-tourmaline characteristic physical properties

    Hardness
    7-7.5
    CharacteristicComments
    Streak
    White
    SpecificGravity
    2.9-3.1
    Toughness
    Good
    Inclusions
    Green elbaite tourmaline stones are type I clarity stones. Blue, purple, orange, yellow and bi-color or parti-colored elbaite tourmalines are type II clarity stones. Stones might contain liquid and gas inclusions that are long and thin, reflective gas-filled fractures and color zoning.
    Luster
    Vitreous
    Stability
    Very Good
    Fracture
    Conchoidal, Uneven
    Cleavage
    Poor, in two directions