Apophyllite Gemstone & Information | Gemopedia by JTV | Gemopedia™

Apophyllite

Apophyllite is divided into three distinct species, fluorapophyllite, hydroxyapophyllite and natroapophyllite, depending on their chemical composition. It was once considered to be a single mineral, so if chemical composition is not yet determined specimens will still be referred to as apophyllite. It is commonly found as glassy prismatic, blocky, or tabular white to grayish or light pastel crystals. The name apophyllite comes from the Greek word meaning "leafs off," referring to its tendency to flake when heated.

Colors

Colorless, White, Reddish, Pink, Pale Yellow, Bluish, Green

  • Apophyllite classification

    CommonName
    Apophyllite
    Species
    Apophyllite
    Variety
    Colors
    Colorless, White, Reddish, Pink, Pale Yellow, Bluish, Green
    AlternateNames
    Fisheye Stone, Apophyllite-(KF)
    GemstoneGroups
    KeySeparations
    RI, birefringence, possible florescence
    ClassificationComments
  • Apophyllite chemistry & crystallography

    ChemicalName
    hydrated potassium calcium silicate fluoride hydroxide
    ChemicalFormula
    KCa4Si8O20(F,OH).8H2O
    Synthesis
    CrystalSystem
    Tetragonal
    ChemistryClassification
    Silicate
    Nature
    Natural
    Crystallinity
    Crystalline
    ChemistryComments
  • Apophyllite optical properties

    Transparency
    Transparent - Translucent
    Dispersion
    Strength: strong fire
    OpticalComments
    RefractiveIndex
    1.535-1.537
    Birefringence
    0-0.002
    OpticCharacter
    Uniaxial
    OpticSign
    Positive or Negative
    PolariscopeReaction
    Doubly Refractive (DR)
    Fluorescence
    SWUV: inert to moderate yellowish white or green
    LWUV: Inert to moderate yellow or yellowish white
    CCFReaction
    Pleochroism
    None
  • Apophyllite characteristic physical properties

    Hardness
    4.5-5
    CharacteristicComments
    Streak
    White
    SpecificGravity
    2.3-2.5
    Toughness
    Poor
    Inclusions
    Luster
    Vitreous
    Stability
    Poor
    Fracture
    Uneven
    Cleavage
    Perfect, in one direction, good in one direction