Satin Spar Gemstone & Information | Gemopedia by JTV | Gemopedia™

Satin Spar

Satin spar is an adjective used when the fibrous habit of a mineral gives it a satin luster. The term satin spar has been used in the past to describe calcite and aragonite, however, it is currently accepted as one variety of the mineral gypsum, along with selenite and alabaster. In addition to its ornamental uses, gypsum is also a primary component in plaster and other building materials.

Colors

Colorless, White, Cream

  • Satin-spar classification

    CommonName
    Satin Spar
    Species
    Gypsum
    Variety
    Satin Spar
    Colors
    Colorless, White, Cream
    AlternateNames
    GemstoneGroups
    KeySeparations
    Appearance, RI and SG. Poor polished surface due to low mohs hardness.
    ClassificationComments
  • Satin-spar chemistry & crystallography

    ChemicalName
    hydrous calcium sulfate
    ChemicalFormula
    CaSO4- 2H2O
    Synthesis
    CrystalSystem
    Monoclinic
    ChemistryClassification
    Sulfate
    Nature
    Natural
    Crystallinity
    Crystalline
    ChemistryComments
  • Satin-spar optical properties

    Transparency
    Translucent
    Dispersion
    OpticalComments
    RefractiveIndex
    1.52-1.529
    Tolerance:(+0.001/-0.001)
    Birefringence
    0.009-0.01
    OpticCharacter
    Biaxial
    OpticSign
    Positive
    PolariscopeReaction
    Doubly Refractive (DR)
    Fluorescence
    SWUV: Inert to weak brownish to greenish white
    LWUV: Inert to weak brownish to greenish white
    CCFReaction
    Pleochroism
    None
  • Satin-spar characteristic physical properties

    Hardness
    1.5-2
    CharacteristicComments
    Streak
    White
    SpecificGravity
    2.25-2.35 Typical:2.3
    Toughness
    Poor
    Inclusions
    Satin spar is a white to cream fibrous gypsum with chatoyant effect.
    Luster
    Waxy
    Stability
    Fair
    Fracture
    Granular
    Cleavage
    None