Tortoise Shell Gemstone & Information | Gemopedia by JTV | Gemopedia™

Tortoise Shell

Tortoise shell used in ornamentation traditionally comes from the shell of the hawksbill sea turtle. The multicolored marbled patterns of the shell are coveted not only for their unique colorations, but also their deep translucence. When heated, the shell becomes soft and can be molded into jewelry and other decorated articles. Due to the depletion of the species today, its use is illegal in many countries and has primarily been replaced by synthetic tortoise shell.

Colors

Mottled Yellow, Brown, Sometimes Black, White

  • Tortoise-shell classification

    CommonName
    Tortoise Shell
    Species
    NA
    Variety
    Colors
    Mottled Yellow, Brown, Sometimes Black, White
    AlternateNames
    GemstoneGroups
    KeySeparations
    Appearance, RI and magnification. Will smell like burning hair during hot point test.
    ClassificationComments
    Hawksbill turtles are an endangered species and importation of tortoise shell is against U.S. law. It is also a protected species under the CITES agreement.
  • Tortoise-shell chemistry & crystallography

    ChemicalName
    keratin
    ChemicalFormula
    Synthesis
    CrystalSystem
    NA
    ChemistryClassification
    Organic
    Nature
    Natural
    Crystallinity
    Amorphous
    ChemistryComments
  • Tortoise-shell optical properties

    Transparency
    Semitransparent - Semitranslucent
    Dispersion
    OpticalComments
    RefractiveIndex
    1.55-1.644
    Tolerance:(-0.010)
    Birefringence
    OpticCharacter
    NA
    OpticSign
    NA
    PolariscopeReaction
    Singly Refractive (SR)
    Fluorescence
    SWUV: Inert to moderate bluish white
    LWUV: Inert to moderate bluish white
    CCFReaction
    Pleochroism
    None
  • Tortoise-shell characteristic physical properties

    Hardness
    2.5
    CharacteristicComments
    Streak
    SpecificGravity
    1.26-1.35 Typical:1.29
    Toughness
    Fair
    Inclusions
    Tortoise shell will have mottled coloration, numerous spherical particles that give it a dot like pattern under magnification. Plastic imitations will have a swirl like pattern.
    Luster
    Waxy
    Stability
    Fracture
    Uneven, Splintery
    Cleavage
    None