Indicolite Gemstone & Information | Gemopedia by JTV | Gemopedia™

Indicolite

Indicolite is one of the most valuable and collectible of all elbaite tourmalines, with hues spanning from lighter to deep, intense blues. Cutting indicolite can be a task for even the most skilled of cutters, as it is strongly pleochroic and appears darker when viewed down the crystal. This factor must be taken into consideration when cutting, as a loss of transparency and brilliance can occur in darker specimens.

Colors

Violet To Greenish Blue

  • Indicolite classification

    CommonName
    Indicolite
    Species
    Elbaite
    Variety
    Indicolite
    Colors
    Violet To Greenish Blue
    AlternateNames
    Indigolite, Aqualite
    GemstoneGroups
    Tourmaline
    KeySeparations
    appearance, refractive index and high birefringence; then optic figure, pleochroism and specific gravity
    ClassificationComments
    Crystal habit is prismatic and may be 3, 6 or 9-sided; often a triangular prism with convex faces, and often long and heavily striated parallel to the c axis. Pyramidal terminations are common. Tourmaline is part of an isomorphous series.Dark material might have a birefringence as high as 0.040
  • Indicolite 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
  • Indicolite optical properties

    Transparency
    Transparent - Opaque
    Dispersion
    Strength: moderate fire Value: 0.017
    OpticalComments
    RefractiveIndex
    1.624-1.644
    Tolerance:-1.22222222222222
    Birefringence
    0.018-0.02
    OpticCharacter
    Uniaxial
    OpticSign
    Negative
    PolariscopeReaction
    Doubly Refractive (DR)
    Fluorescence
    SWUV: Inert to weak bluish green
    LWUV: Inert to weak bluish green
    CCFReaction
    Pleochroism
    Dichroic, strong dark blue and light blue
  • Indicolite characteristic physical properties

    Hardness
    7-7.5
    CharacteristicComments
    Streak
    White
    SpecificGravity
    3-3.26 Range:0.2/-0.06 Typical:3.06
    Toughness
    Good
    Inclusions
    Indicolite is a type II clarity. stone. 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
    Cleavage
    Poor, in two directions