Danburite Gemstone & Information | Gemopedia by JTV | Gemopedia™

Danburite

In 1839 American mineralogist Charles Upham Shephard discovered a clear, bright, colorless gemstone in Danbury, Connecticut, and named it danburite after the location. Unfortunately for danburite, it was discovered at a time when colored gemstones were heavily promoted and highly desired. This colorless find, therefore, didn't create much excitement at that time. Danburite, which belongs to a class of minerals known as silicates, remained relatively unknown for years, but is steadily growing in popularity today.

Colors

Colorless, Light Yellow To Brown, Light Pink

  • Danburite classification

    CommonName
    Danburite
    Species
    Danburite
    Variety
    Colors
    Colorless, Light Yellow To Brown, Light Pink
    AlternateNames
    GemstoneGroups
    KeySeparations
    RI, birefringence, optic character and SG. Biaxial positive or negative with the common point halfway between highest RI and lowest RI.
    ClassificationComments
    Danburite can be chatoyant if it has parallel growth tubes.
  • Danburite chemistry & crystallography

    ChemicalName
    calcium boron silicate
    ChemicalFormula
    CaB2(SiO4)2
    Synthesis
    CrystalSystem
    Orthorhombic
    ChemistryClassification
    Silicate
    Nature
    Natural
    Crystallinity
    Crystalline
    ChemistryComments
  • Danburite optical properties

    Transparency
    Transparent - Translucent
    Dispersion
    Strength: weak fire Value: 0.016
    OpticalComments
    RefractiveIndex
    1.63-1.636
    Tolerance:(+0.003/-0.003)
    Birefringence
    0.006
    OpticCharacter
    Biaxial
    OpticSign
    Positive or Negative
    PolariscopeReaction
    Doubly Refractive (DR)
    Fluorescence
    SWUV: inert to weaker, light blue to blue-green
    LWUV: inert to strong, light blue to blue-green
    CCFReaction
    Pleochroism
    Dichroic, unobservable or weak, varying shades of body color
  • Danburite characteristic physical properties

    Hardness
    7
    CharacteristicComments
    Streak
    White
    SpecificGravity
    2.97-3.03 Typical:3
    Toughness
    Good
    Inclusions
    Danburite might have natural inclusions, fingerprints and parallel growth tubes.
    Luster
    Vitreous
    Stability
    Fracture
    Uneven, Subconchoidal
    Cleavage
    None