Bytownite Gemstone & Information | Gemopedia by JTV | Gemopedia™

Bytownite

Bytownite is a rare variety of feldspar named for deposits found in Bytown, Canada (now Ottawa). Some forms of this gem distinctly resemble the gemstone andalusite, another member of the feldspar group.

Colors

Pale Yellow, Colorless, White, Gray

  • Bytownite classification

    CommonName
    Bytownite
    Species
    Anorthite
    Variety
    Bytownite
    Colors
    Pale Yellow, Colorless, White, Gray
    AlternateNames
    GemstoneGroups
    Feldspar
    KeySeparations
    RI and optic character
    ClassificationComments
    Bytownite can have a similar appearance to andalusite.
  • Bytownite chemistry & crystallography

    ChemicalName
    calcium sodium aluminum silicate
    ChemicalFormula
    (Ca,Na)(Al,Si)AlSi2O8
    Synthesis
    CrystalSystem
    Triclinic
    ChemistryClassification
    Silicate
    Nature
    Natural
    Crystallinity
    Crystalline
    ChemistryComments
  • Bytownite optical properties

    Transparency
    Transparent - Translucent
    Dispersion
    Strength: weak fire Value: 0.012
    OpticalComments
    RefractiveIndex
    1.561-1.583
    Birefringence
    0.007-0.011
    OpticCharacter
    Biaxial
    OpticSign
    Negative
    PolariscopeReaction
    Doubly Refractive (DR)
    Fluorescence
    SWUV: Inert
    LWUV: Inert
    CCFReaction
    Pleochroism
    Unobservable
  • Bytownite characteristic physical properties

    Hardness
    6-6.5
    CharacteristicComments
    Streak
    White
    SpecificGravity
    2.72-2.74
    Toughness
    Poor
    Inclusions
    Bytownite might show labradorescence.
    Luster
    Vitreous
    Stability
    Fracture
    Conchoidal, Uneven
    Cleavage
    Perfect, in one direction, Good, in one direction