Herderite Gemstone & Information | Gemopedia by JTV | Gemopedia™

Herderite

Herderite is a rare collector gem, typically found in smaller sizes. This mineral occurs in orange, yellow green and blue colors. Herderite was first discovered in Germany in 1828, but Brazil is today's dominant source. Collectors treasure herderite for its often present twinned crystal formation and some specimens exhibit fluorescence.

Colors

Grayish Blue, Yellow, Pink, Violet, Green, Colorless

  • Herderite classification

    CommonName
    Herderite
    Species
    Herderite
    Variety
    Colors
    Grayish Blue, Yellow, Pink, Violet, Green, Colorless
    AlternateNames
    GemstoneGroups
    KeySeparations
    ClassificationComments
  • Herderite chemistry & crystallography

    ChemicalName
    ChemicalFormula
    CaBePO4(F,OH)
    Synthesis
    CrystalSystem
    Monoclinic
    ChemistryClassification
    Phosphate
    Nature
    Natural
    Crystallinity
    Crystalline
    ChemistryComments
  • Herderite optical properties

    Transparency
    Transparent - Translucent
    Dispersion
    Strength: none
    OpticalComments
    RefractiveIndex
    1.587-1.627
    Birefringence
    0.023-0.032
    OpticCharacter
    Biaxial
    OpticSign
    Positive or Negative
    PolariscopeReaction
    Doubly Refractive (DR)
    Fluorescence
    SWUV: Inert to moderate yellowish white, blue or violet
    LWUV: Inert to weak yellowish white
    CCFReaction
    Pleochroism
    Unobservable
  • Herderite characteristic physical properties

    Hardness
    5-5.5
    CharacteristicComments
    Streak
    White
    SpecificGravity
    2.95-3.02
    Toughness
    Poor
    Inclusions
    Luster
    Vitreous
    Stability
    Poor
    Fracture
    Subconchoidal
    Cleavage
    Good, in one direction