Xaxim Gemstone & Information | Gemopedia by JTV | Gemopedia™

Xaxim

Xaxim is a type of petrified tree fern from a period of time even before the dinosaurs roamed the earth. Estimated to be some 270 million years old, these fossilized specimens offer an exciting window into the past. Similar in appearance to the palm tree, xaxim trees can still be found growing in Brazil today. However, they grow very slowly, averaging about 3 inches every 10 years. Featuring all natural color with no enhancement, xaxim is prized by fossil collectors across the globe.

Colors

Tan, Cream, Brown, Orange, White, Gray, Black, Yellow, Red

  • Xaxim classification

    CommonName
    Xaxim
    Species
    Quartz
    Variety
    Chalcedony
    Colors
    Tan, Cream, Brown, Orange, White, Gray, Black, Yellow, Red
    AlternateNames
    Fossilized Tree Fern, Agatized Fossil Tree Fern, Petrified Tree Fern
    GemstoneGroups
    KeySeparations
    RI, SG, appearance and fracture
    ClassificationComments
    Xaxim is estimated to be 270 million years old.
  • Xaxim chemistry & crystallography

    ChemicalName
    silicon dioxide (aka silica)
    ChemicalFormula
    SiO2
    Synthesis
    CrystalSystem
    Trigonal
    ChemistryClassification
    Silicate
    Nature
    Natural
    Crystallinity
    Aggregate
    ChemistryComments
  • Xaxim optical properties

    Transparency
    Semitransparent - Semitranslucent
    Dispersion
    Strength: none
    OpticalComments
    RefractiveIndex
    1.539-1.535
    Birefringence
    0.004-0.004
    OpticCharacter
    Uniaxial
    OpticSign
    Positive
    PolariscopeReaction
    Aggregate (AGG)
    Fluorescence
    SWUV: Inert
    LWUV: Inert
    CCFReaction
    Pleochroism
    None
  • Xaxim characteristic physical properties

    Hardness
    6.5-7
    CharacteristicComments
    Streak
    SpecificGravity
    2.55-2.7 Typical:2.6
    Toughness
    Excellent
    Inclusions
    Xaxim's cellular appearance comes from the cross section structure of the fern.
    Luster
    Vitreous
    Stability
    Good
    Fracture
    Conchoidal, Granular
    Cleavage
    None