Natrolite Gemstone & Information | Gemopedia by JTV | Gemopedia™

Natrolite

Natrolite is a zeolite mineral named for the Greek word natron meaning "soda" due to the presence of sodium in the stone. Its range of colors include yellow, gray, brown to colorless. Occasionally, it is found in pale yellow to red hues. Crystals often grow in long, needle-like formations, and are especially prized by specimen collectors.

Colors

White, Colorless, Reddish, Greenish, Brownish, Yellowish.

  • Natrolite classification

    CommonName
    Natrolite
    Species
    Natrolite
    Variety
    Colors
    White, Colorless, Reddish, Greenish, Brownish, Yellowish.
    AlternateNames
    GemstoneGroups
    KeySeparations
    RI, appearance and possibly fluorescence.
    ClassificationComments
    Sometimes pyroelectric: development of opposite charges at the ends of the crystal due to change in temperature. Sometimes piezoelectric: development of opposite charges at the ends of the crystal when placed under stress.
  • Natrolite chemistry & crystallography

    ChemicalName
    hydrated sodium aluminum silicate
    ChemicalFormula
    Na2[Al2Si3O10].2H2O
    Synthesis
    CrystalSystem
    Orthorhombic
    ChemistryClassification
    Silicate
    Nature
    Natural
    Crystallinity
    Crystalline to Aggregate
    ChemistryComments
  • Natrolite optical properties

    Transparency
    Transparent - Opaque
    Dispersion
    Strength: weak fire Value: 0.005
    OpticalComments
    RefractiveIndex
    1.48-1.493
    Birefringence
    0.012-0.013
    OpticCharacter
    Biaxial
    OpticSign
    Positive
    PolariscopeReaction
    Doubly Refractive (DR)
    Fluorescence
    SWUV: Inert to strong green
    LWUV: Inert to weak greenish white
    CCFReaction
    Pleochroism
    Unobservable
  • Natrolite characteristic physical properties

    Hardness
    5-5.5
    CharacteristicComments
    Streak
    White
    SpecificGravity
    2.2-2.26
    Toughness
    Poor
    Inclusions
    Natrolite is usually found as a fibrous aggregate. Stones might have yellowish brown acmite inclusions that appear rod-like.
    Luster
    Vitreous
    Stability
    Fracture
    Uneven
    Cleavage
    Perfect, in one direction