Ethiopian Opal Gemstone & Information | Gemopedia by JTV | Gemopedia™

Ethiopian Opal

Opal with play of color has always been considered one of the most desired gems in the marketplace, earning it the undisputed title as 'Queen of Gemstones'. With the discovery of precious (and stable) opal in Ethiopia's northern Welo District in 2008, coupled with its prolific bounty, this remarkable gem has reclaimed its throne and rules again as one of the most in-demand gemstones in the 21st century.

Colors

Colorless, White, Yellow, Orange, Brown

  • Ethiopian-opal classification

    CommonName
    Ethiopian Opal
    Species
    Opal
    Variety
    Ethiopian Opal
    Colors
    Colorless, White, Yellow, Orange, Brown
    AlternateNames
    GemstoneGroups
    KeySeparations
    Key tests are play-of-color, refractive index and fluorescence. Opals might phosphoresce, and this is a strong indication of its natural origins, as synthetic or simulant opals do not phosphoresce.
    ClassificationComments
    Many Ethiopian opals are hydrophane opal which is porous and will take on water. The SG of stones can be variable due to soaking in liquid or due to the humidity of surrounding atmosphere.
  • Ethiopian-opal chemistry & crystallography

    ChemicalName
    silica
    ChemicalFormula
    SiO2-nH2O
    Synthesis
    CrystalSystem
    NA
    ChemistryClassification
    Silicate
    Nature
    Natural
    Crystallinity
    Polycrystalline
    ChemistryComments
  • Ethiopian-opal optical properties

    Transparency
    Transparent - Opaque
    Dispersion
    Strength: none
    OpticalComments
    RefractiveIndex
    1.45
    Tolerance:-0.25
    Birefringence
    OpticCharacter
    NA
    OpticSign
    NA
    PolariscopeReaction
    Singly Refractive (SR) With ADR
    Fluorescence
    SWUV: Variable
    LWUV: Variable
    CCFReaction
    Pleochroism
    None
  • Ethiopian-opal characteristic physical properties

    Hardness
    5-6.5
    CharacteristicComments
    Streak
    White
    SpecificGravity
    1.25-2.23 Typical:2.15
    Toughness
    Varies
    Inclusions
    Ethiopian opal will have play-of-color in various patterns, such as pinfire (small patches or dots), flash (large areas of color), harlequin (brush-strokes of color); flagstone and other unique patterns.
    Luster
    Vitreous
    Stability
    Poor
    Fracture
    Conchoidal, Uneven
    Cleavage
    None