Prasiolite Gemstone & Information | Gemopedia by JTV | Gemopedia™

Prasiolite

A pastel dream, this variety of quartz boasts a beautiful soft green color. Sometimes called "green amethyst" or "lime citrine," prasiolite is rarely found in nature, so most material available on the market is produced by heating or irradiating amethyst or citrine. Prasiolite is an exciting gem in that it is readily available in large sizes with high transparency and great durability.

Colors

Green To Yellowish Green

  • Prasiolite classification

    CommonName
    Prasiolite
    Species
    Quartz
    Variety
    Prasiolite
    Colors
    Green To Yellowish Green
    AlternateNames
    Green Quartz, "Greened Amethyst"
    GemstoneGroups
    KeySeparations
    Refractive index, birefringence, optic character and optic figure. A bull's-eye optic figure is determinative for quartz. The presence of Brazil-law twinning is a means of separating amethyst from scapolite.
    ClassificationComments
    Misnomer: green amethyst. Green color is rarely found naturally and most are irradiated and/or heat treated.
  • Prasiolite chemistry & crystallography

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

    Transparency
    Transparent - Translucent
    Dispersion
    Strength: weak fire Value: 0.013
    OpticalComments
    RefractiveIndex
    1.544-1.553
    Tolerance:very constant
    Birefringence
    0.009
    OpticCharacter
    Uniaxial
    OpticSign
    Positive
    PolariscopeReaction
    Doubly Refractive (DR)
    Fluorescence
    SWUV: Inert
    LWUV: Inert
    CCFReaction
    Pleochroism
    Dichroic, unobservable or weak, varying shades of body color
  • Prasiolite characteristic physical properties

    Hardness
    7
    CharacteristicComments
    Streak
    White
    SpecificGravity
    2.64-2.69 Typical:2.66
    Toughness
    Good
    Inclusions
    Prasiolite is a type II clarity stone. Stones may contain crystals, negative crystals, liquid inclusions, two-phase inclusions and partially-healed fractures.
    Luster
    Vitreous
    Stability
    Good
    Fracture
    Conchoidal
    Cleavage
    None