Sphene Gemstone & Information | Gemopedia by JTV | Gemopedia™

Sphene

A brilliantly transparent gem, sphene has fire greater than that of diamond! This gem is named from the Greek word for "wedge," as its crystals are typically wedge shaped, but may be referred to by its mineral name, titanite. On rare instances, sphene may be pink, brown or black in color, but is mainly found in a range of green to yellowish green colors. Another characteristic sphene possesses is birefringence, or double refraction, meaning that light splits into two rays as it passes through the gem. As a result, the back facets appear as double images, giving the gem a soft, hazy appearance, similar to the doubling seen in zircon.

Colors

Yellow, Green, Brown, Orange, Red

  • Sphene classification

    CommonName
    Sphene
    Species
    Sphene
    Variety
    Colors
    Yellow, Green, Brown, Orange, Red
    AlternateNames
    Titanite, Chrome Sphene
    GemstoneGroups
    KeySeparations
    OTL RI reading, very strong eye visible doubling, possibly spectra
    ClassificationComments
    Chrome sphene is intense green in color.
  • Sphene chemistry & crystallography

    ChemicalName
    calcium titanium silicate
    ChemicalFormula
    CaTiSiO5
    Synthesis
    CrystalSystem
    Monoclinic
    ChemistryClassification
    Silicate
    Nature
    Natural
    Crystallinity
    Crystalline
    ChemistryComments
  • Sphene optical properties

    Transparency
    Transparent - Translucent
    Dispersion
    Strength: strong fire Value: 0.051
    OpticalComments
    RefractiveIndex
    Over The Limit 1.9-2.034
    Tolerance:(+0.020/-0.020)
    Birefringence
    0.1-0.135
    OpticCharacter
    Biaxial
    OpticSign
    Positive
    PolariscopeReaction
    Doubly Refractive (DR)
    Fluorescence
    SWUV: Inert
    LWUV: Inert
    CCFReaction
    Pleochroism
    Trichroic, (in green gems) strong greenish yellow, yellow to brown, and colorless; (in brown gems) strong yellow, reddish-orange, and brownish yellow and brownish orange, (in yellow gems) moderate to strong greenish yellow, brownish-orange, and colorless
  • Sphene characteristic physical properties

    Hardness
    5-5.5
    CharacteristicComments
    Streak
    White
    SpecificGravity
    3.5-3.54 Typical:3.52
    Toughness
    Varies
    Inclusions
    Sphene occasionally contain tiny crystals that aline in straight rows or "feathers", natural inclusions, actinolite needles and twinning is common. Stones have strong dispersion and eye-visible doubling.
    Luster
    SubAdamantine
    Stability
    Fracture
    Conchoidal, Splintery
    Cleavage
    Good, in one direction