Phenakite Gemstone & Information | Gemopedia by JTV | Gemopedia™

Phenakite

A rare beryllium mineral, phenakite was named in 1833 from the Greek word for "deceiver," alluding to its similar appearance to quartz. Its crystals are predominantly rhombohedral, and less commonly short and prismatic. Phenakite's rarity, hardness, lack of cleavage and high clarity make it a great option for collectors.

Colors

Colorless To Light Yellow, Light Brown, Pink, Greenish Blue

  • Phenakite classification

    CommonName
    Phenakite
    Species
    Phenakite
    Variety
    Colors
    Colorless To Light Yellow, Light Brown, Pink, Greenish Blue
    AlternateNames
    Phenacite
    GemstoneGroups
    KeySeparations
    Optic character, SG, birefringence and possibly cleavage and fluorescence
    ClassificationComments
  • Phenakite chemistry & crystallography

    ChemicalName
    beryllium silicate
    ChemicalFormula
    Be2SiO4
    Synthesis
    CrystalSystem
    Hexagonal
    ChemistryClassification
    Silicate
    Nature
    Natural
    Crystallinity
    Crystalline
    ChemistryComments
  • Phenakite optical properties

    Transparency
    Transparent
    Dispersion
    Strength: weak fire Value: 0.015
    OpticalComments
    RefractiveIndex
    1.654-1.67
    Tolerance:(+0.026/-0.004)
    Birefringence
    0.016
    OpticCharacter
    Uniaxial
    OpticSign
    Positive
    PolariscopeReaction
    Doubly Refractive (DR)
    Fluorescence
    SWUV: Inert to weak pink, light blue or green
    LWUV: Inert to weak pink, light blue or green
    CCFReaction
    Pleochroism
    Dichroic, weak to moderate, varying shades of body color
  • Phenakite characteristic physical properties

    Hardness
    7.5-8
    CharacteristicComments
    Streak
    White
    SpecificGravity
    2.9-3 Typical:2.95
    Toughness
    Good
    Inclusions
    Luster
    Vitreous
    Stability
    Fracture
    Conchoidal
    Cleavage
    Good, in one direction, Poor, in one direction