Actinolite Gemstone & Information | Gemopedia by JTV | Gemopedia™

Actinolite

Generally transparent or translucent green, green-black, or grey-green in color, actinolite is named after the Greek word for "ray" or "beam," aktinos, referring to its fibrous nature. Actinolite also goes by the nickname 'ray stone' and is fairly prevalent worldwide.

Colors

Light To Dark Green, Yellowish Green, Brown, White, Gray, Black

  • Actinolite classification

    CommonName
    Actinolite
    Species
    Actinolite
    Variety
    Colors
    Light To Dark Green, Yellowish Green, Brown, White, Gray, Black
    AlternateNames
    Smaragdite
    GemstoneGroups
    Amphibole
    KeySeparations
    RI, appearance, magnification polariscope reaction, spectrum. Parallel fibrous structure in cat's eye stones.
    ClassificationComments
    Actinolite usually fibrous aggregate. Misnomer jade cat's-eye.Smaragdite is the emerald green variety of actinolite.
  • Actinolite chemistry & crystallography

    ChemicalName
    calcium magnesium iron silicate hydroxide
    ChemicalFormula
    Ca2(Mg, Fe)5Si8O22(OH)2
    Synthesis
    CrystalSystem
    Monoclinic
    ChemistryClassification
    Silicate
    Nature
    Natural
    Crystallinity
    Crystalline to Aggregate
    ChemistryComments
  • Actinolite optical properties

    Transparency
    Transparent - Opaque
    Dispersion
    Strength: none
    OpticalComments
    RefractiveIndex
    1.614-1.164
    Tolerance:(+0.014/-0.014)
    Birefringence
    0.022-0.027
    OpticCharacter
    Biaxial
    OpticSign
    Negative
    PolariscopeReaction
    Doubly Refractive (DR)
    Fluorescence
    SWUV: Inert
    LWUV: Inert
    CCFReaction
    Pleochroism
    Dichroic, moderate yellow and dark green.
  • Actinolite characteristic physical properties

    Hardness
    5-6
    CharacteristicComments
    Streak
    White
    SpecificGravity
    2.95-3.1 Typical:3
    Toughness
    Varies
    Inclusions
    It is the fibrous structure that causes chatoyancy.
    Luster
    Vitreous
    Stability
    Good
    Fracture
    Even
    Cleavage
    Perfect, in two directions