Euclase Gemstone & Information | Gemopedia by JTV | Gemopedia™

Euclase

Although euclase can resemble beryl in its appearance, that is where the comparison ends. Unlike beryl, euclase contains water, has a monoclinic crystal system and a higher specific gravity. It is only occasionally that its well-formed crystals have sufficient clarity to be cut as gemstones. Crystals are commonly prismatic, can be long or short and are striated. Because of their rarity, gems with good clarity command premium prices. Most material is colorless to pale blue or pale green, but colors can range from blue to blue-green, green, yellow, white, colorless, and, rarely, purple.

Colors

Colorless, Yellowish To Bluish Green, Blue To Greenish Blue

  • Euclase classification

    CommonName
    Euclase
    Species
    Euclase
    Variety
    Colors
    Colorless, Yellowish To Bluish Green, Blue To Greenish Blue
    AlternateNames
    GemstoneGroups
    KeySeparations
    RI, birefringence and optic character
    ClassificationComments
  • Euclase chemistry & crystallography

    ChemicalName
    beryllium aluminum silicate hydroxide
    ChemicalFormula
    BeAlSiO4OH
    Synthesis
    CrystalSystem
    Monoclinic
    ChemistryClassification
    Silicate
    Nature
    Natural
    Crystallinity
    Crystalline
    ChemistryComments
  • Euclase optical properties

    Transparency
    Transparent
    Dispersion
    Strength: weak fire Value: 0.016
    OpticalComments
    RefractiveIndex
    1.652-1.671
    Tolerance:(+0.006/-0.002)
    Birefringence
    0.019-0.02
    OpticCharacter
    Biaxial
    OpticSign
    Positive
    PolariscopeReaction
    Doubly Refractive (DR)
    Fluorescence
    SWUV: inert to weak pale yellow
    LWUV: inert to weak red
    CCFReaction
    Pleochroism
    Trichroic, unobservable or weak, colorless, yellowish green, and blue-green
  • Euclase characteristic physical properties

    Hardness
    7.5
    CharacteristicComments
    Streak
    White
    SpecificGravity
    3-3.12 Typical:3.08
    Toughness
    Poor
    Inclusions
    Euclase can contain quartz and fluid inclusions. Red or blue plate like inclusions and dark gray metallic inclusions of bravoite are possible. Colorless stones or pale yellow stones might have blue-green color zoning.
    Luster
    Vitreous
    Stability
    Fracture
    Conchoidal
    Cleavage
    Perfect, in one direction, Good, in two directions