Dumortierite Gemstone & Information | Gemopedia by JTV | Gemopedia™

Dumortierite

A mineral that often forms as an inclusion in quartz, dumortierite is a mineral that is often fashioned as cabochons or beads for jewelry. While prized for its deep violet to blue colors, it may also be found in shades of pink, gray and brown. Named for French paleontologist Eugne Dumortier, dumortierite is an exotic gem that is durable, untreated and rare.

Colors

Dark Blue, Violet Blue, Greenish Blue, Green, Red-Brown, Colorless

  • Dumortierite classification

    CommonName
    Dumortierite
    Species
    Dumortierite
    Variety
    Colors
    Dark Blue, Violet Blue, Greenish Blue, Green, Red-Brown, Colorless
    AlternateNames
    GemstoneGroups
    KeySeparations
    RI and SG
    ClassificationComments
    Dumortierite is often found as inclusions in quartz.
  • Dumortierite chemistry & crystallography

    ChemicalName
    ChemicalFormula
    Al7(BO3)(SiO4)3O3
    Synthesis
    CrystalSystem
    Orthorhombic
    ChemistryClassification
    Silicate
    Nature
    Natural
    Crystallinity
    Crystalline to Aggregate
    ChemistryComments
  • Dumortierite optical properties

    Transparency
    Translucent - Opaque
    Dispersion
    Strength: none
    OpticalComments
    RefractiveIndex
    1.678-1.689
    Birefringence
    0.015-0.037
    OpticCharacter
    Biaxial
    OpticSign
    Negative
    PolariscopeReaction
    Doubly Refractive (DR)
    Fluorescence
    SWUV: Moderate bluish white
    LWUV: Inert to yellowish white or red
    CCFReaction
    Pleochroism
    Unobservable
  • Dumortierite characteristic physical properties

    Hardness
    7-8.5
    CharacteristicComments
    Streak
    White
    SpecificGravity
    3.26-3.41
    Toughness
    Inclusions
    Dumortierite is most common in its fibrous or granular structured variety.
    Luster
    Vitreous
    Stability
    Fracture
    Conchoidal
    Cleavage
    Good, in one direction, Poor, in one direction