Astrophyllite Gemstone & Information | Gemopedia by JTV | Gemopedia™

Astrophyllite

Astrophyllite is golden-yellow to dark brown and usually forms as bladed crystals radiating from a common center. It gets its name from the Greek astron, meaning "star", and phyllon, meaning "leaf." It may also be translated as "star sheets," fitting because of the interwoven star shapes that the crystals sometimes form and because of its strange luster, which can be metallic in some crystals and pearly in others. Although there are occurrences of astrophyllite around the world, some of the finest crystals come from remote mountainous regions in arctic northern Russia.

Colors

Brown, Reddish Brown, Golden Yellow, Bronze Like

  • Astrophyllite classification

    CommonName
    Astrophyllite
    Species
    Astrophyllite
    Variety
    Colors
    Brown, Reddish Brown, Golden Yellow, Bronze Like
    AlternateNames
    GemstoneGroups
    KeySeparations
    RI, optic character and appearance
    ClassificationComments
  • Astrophyllite chemistry & crystallography

    ChemicalName
    potassium sodium iron manganese titanium silicate hydroxide
    ChemicalFormula
    (K,Na)3(Fe2+,Mn)7Ti2Si8O24(O,OH)7
    Synthesis
    CrystalSystem
    Triclinic
    ChemistryClassification
    Silicate
    Nature
    Natural
    Crystallinity
    Crystalline to Aggregate
    ChemistryComments
  • Astrophyllite optical properties

    Transparency
    Translucent - Opaque
    Dispersion
    Strength: strong fire
    OpticalComments
    RefractiveIndex
    1.678-1.758
    Birefringence
    OpticCharacter
    Biaxial
    OpticSign
    Positive
    PolariscopeReaction
    Doubly Refractive (DR)
    Fluorescence
    SWUV:
    LWUV:
    CCFReaction
    Pleochroism
    Trichroic, orangy red, orangy yellow, yellow
  • Astrophyllite characteristic physical properties

    Hardness
    3
    CharacteristicComments
    Streak
    Golden
    SpecificGravity
    3.2-3.4
    Toughness
    Poor
    Inclusions
    The stone is composed of star or leaf like sheets some of which can have a metallic or pearly luster.
    Luster
    Greasy
    Stability
    Fracture
    Uneven
    Cleavage
    Perfect, in one direction, Poor, in one direction