Prosopite Gemstone & Information | Gemopedia by JTV | Gemopedia™

Prosopite

The mineral prosopite is named from the Greek word prosopon, meaning mask, most likely a reference to its pseudomorphic forms. It typically ranges in color from white to gray to colorless. There is a beautiful blue Mexican variety that resembles softly colored turquoise that is of particular interest to collectors.

Colors

Robin's Egg Blue, Colorless To Grayish White

  • Prosopite classification

    CommonName
    Prosopite
    Species
    Prosopite
    Variety
    Colors
    Robin's Egg Blue, Colorless To Grayish White
    AlternateNames
    GemstoneGroups
    KeySeparations
    RI, SG and possibly specrtum
    ClassificationComments
  • Prosopite chemistry & crystallography

    ChemicalName
    calcium aluminum flouride hydroxide
    ChemicalFormula
    CaAl2(F,OH)8
    Synthesis
    CrystalSystem
    Monoclinic
    ChemistryClassification
    Halide
    Nature
    Natural
    Crystallinity
    Aggregate
    ChemistryComments
  • Prosopite optical properties

    Transparency
    Transparent - Opaque
    Dispersion
    Strength: none
    OpticalComments
    RefractiveIndex
    1.501-1.51
    Birefringence
    0.009
    OpticCharacter
    Biaxial
    OpticSign
    Positive
    PolariscopeReaction
    Doubly Refractive (DR)
    Fluorescence
    SWUV: Inert
    LWUV: Inert
    CCFReaction
    Pleochroism
    Unobservable
  • Prosopite characteristic physical properties

    Hardness
    4.5
    CharacteristicComments
    Streak
    SpecificGravity
    2.69-2.9 Typical:2.88
    Toughness
    Fair
    Inclusions
    Luster
    Vitreous
    Stability
    Fracture
    Conchoidal, Uneven
    Cleavage
    Perfect, in one direction