Ametrine Gemstone & Information | Gemopedia by JTV | Gemopedia™

Ametrine

Ametrine is a bi-color quartz variety that, as its name suggests, is a unique combination of amethyst and citrine within a single crystal. How the gem forms is still a bit of a mystery, but the differences in color are believed to be the result of the presence of iron in different states of oxidation from natural heating. Combining the golden sunburst of citrine with the violet sunset of amethyst, this naturally colored gem is commercially mined at a single source: the remote Anah mine in Bolivia and is shrouded in fascinating local legends and lore.

Colors

Bicolored Combination Of Purple, Yellow

  • Ametrine classification

    CommonName
    Ametrine
    Species
    Quartz
    Variety
    Ametrine
    Colors
    Bicolored Combination Of Purple, Yellow
    AlternateNames
    Trystine, Bolivianite, Amethyst-Citrine, Citrine-Amethyst, Golden Amethyst
    GemstoneGroups
    KeySeparations
    Ametrine's appearance is distinctive and otherwise the key quartz indicators will be present (refractive index, birefringence, optic character and optic figure). A bull's-eye optic figure is determinative for quartz. Might also show Airy's spiral.
    ClassificationComments
    Stones might be piezoelectric: able to generate electricity produced by mechanical pressure,Pyroelectricity: development of opposite charges at the ends of the axis due to change in temperature and triboluminescent: luminescence produced by friction.
  • Ametrine chemistry & crystallography

    ChemicalName
    silicon dioxide (aka silica)
    ChemicalFormula
    SiO2
    Synthesis
    CrystalSystem
    Trigonal
    ChemistryClassification
    Silicate
    Nature
    Natural
    Crystallinity
    Crystalline
    ChemistryComments
  • Ametrine optical properties

    Transparency
    Transparent - Translucent
    Dispersion
    Strength: weak fire Value: 0.013
    OpticalComments
    RefractiveIndex
    1.544-1.553
    Tolerance:very constant
    Birefringence
    0.009-0.009
    OpticCharacter
    Uniaxial
    OpticSign
    Positive
    PolariscopeReaction
    Doubly Refractive (DR)
    Fluorescence
    SWUV: Inert
    LWUV: Inert
    CCFReaction
    Pleochroism
    Dichroic, weak yellow-orange and purple
  • Ametrine characteristic physical properties

    Hardness
    7
    CharacteristicComments
    Streak
    White
    SpecificGravity
    2.64-2.69 Range:0.03/-0.02 Typical:2.66
    Toughness
    Good
    Inclusions
    Ametrine is a type II clarity stone. Color zoning in stones is often present in the form of "soap scum", "tiger stripes" or "zebra stripes", crystals, negative crystals, liquid inclusions, two-phase inclusions, partially-healed fractures, hematite needles.
    Luster
    Vitreous
    Stability
    Good
    Fracture
    Conchoidal
    Cleavage
    None