Plasma Gemstone & Information | Gemopedia by JTV | Gemopedia™

Plasma

Plasma is the term for a deep green chalcedony that often shows small yellow, red or white spots.

Colors

Dark Green With White, Yellowish Spots

  • Plasma classification

    CommonName
    Plasma
    Species
    Quartz
    Variety
    Chalcedony
    Colors
    Dark Green With White, Yellowish Spots
    AlternateNames
    GemstoneGroups
    KeySeparations
    RI, SG, appearance and fracture
    ClassificationComments
  • Plasma chemistry & crystallography

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

    Transparency
    Semitransparent - Opaque
    Dispersion
    Strength: none
    OpticalComments
    RefractiveIndex
    1.535-1.539
    Birefringence
    0.004-0.004
    OpticCharacter
    Uniaxial
    OpticSign
    Positive
    PolariscopeReaction
    Aggregate (AGG)
    Fluorescence
    SWUV: Inert
    LWUV: Inert
    CCFReaction
    Pleochroism
    None
  • Plasma characteristic physical properties

    Hardness
    6.5-7
    CharacteristicComments
    Streak
    White
    SpecificGravity
    2.55-2.7 Typical:2.6
    Toughness
    Excellent
    Inclusions
    Plasma is dark green with white or yellowish spots. The stones semitransparent to opaque nature is what separates plasma from other chalcedonies.
    Luster
    Vitreous
    Stability
    Good
    Fracture
    Conchoidal, Granular
    Cleavage
    None