Ruby Gemstone & Information | Gemopedia by JTV | Gemopedia™

Ruby

The sole birthstone for July, ruby is the brightest and boldest of all birthstones. Called ratnaraj, meaning the "King of Gems" by ancient Hindus, ruby's association with the blood of life has earned it powerful praise and high esteem since antiquity. Ruby is mentioned at least four times in the Bible, always in reference to beauty and wisdom. Its passionate red color makes ruby an ideal choice for a romantic gift that comes with a rich legacy.

Colors

Slightly Orangy Red To Strong Red, Slightly To Purplish Red, Brownish Red

  • Ruby classification

    CommonName
    Ruby
    Species
    Corundum
    Variety
    Ruby
    Colors
    Slightly Orangy Red To Strong Red, Slightly To Purplish Red, Brownish Red
    AlternateNames
    GemstoneGroups
    KeySeparations
    refractive index, birefringence, pleochroism, magnification and spectrum. The observation of natural internal characteristics is a key element in distinguishing natural ruby from its synthetic counterparts.
    ClassificationComments
  • Ruby chemistry & crystallography

    ChemicalName
    aluminum oxide
    ChemicalFormula
    Al2O3
    Synthesis
    CrystalSystem
    Trigonal
    ChemistryClassification
    Oxide
    Nature
    Natural
    Crystallinity
    Crystalline
    ChemistryComments
  • Ruby optical properties

    Transparency
    Transparent - Opaque
    Dispersion
    Strength: moderate fire Value: 0.018
    OpticalComments
    RefractiveIndex
    1.762-1.77
    Tolerance:(+0.009/-0.005)
    Birefringence
    0.008-0.01
    OpticCharacter
    Uniaxial
    OpticSign
    Negative
    PolariscopeReaction
    Doubly Refractive (DR)
    Fluorescence
    SWUV: Weak to strong red
    LWUV: Weak to moderate red
    CCFReaction
    Red glow
    Pleochroism
    Dichroic, moderate to strong orangy red and purplish red
  • Ruby characteristic physical properties

    Hardness
    9
    CharacteristicComments
    Streak
    White
    SpecificGravity
    3.95-4.1 Typical:4
    Toughness
    Excellent
    Inclusions
    This stone has type II clarity. Sometimes rubies have silk, rutile, boehmite, apatite, calcite or zircon crystals, fingerprint and negative crystal inclusions. Some stones show hexagonal growth and color zoning. Untreated stones will usually have inclusions intact. Heat treated stones will have fracture halos, discoid fractures or snowballs around crystal inclusions (untreated stones from magmatic areas might also show these characteristics). Silk will be broken and might show sintered areas especially around the girdle.
    Luster
    Bright Vitreous
    Stability
    Excellent
    Fracture
    Conchoidal, Uneven
    Cleavage
    None