Ruby (Synthetic Star - Czochralski) Gemstone & Information | Gemopedia by JTV | Gemopedia™
Synthetic star ruby exhibits the optical phenomenon called asterism, a star-like pattern created on the surface of a gemstone when light encounters parallel fibrous, or needle-like, inclusions within its crystal structure. Light that strikes the inclusions within the gem reflects off of the inclusions, creating a narrow band of light. When two or more intersecting bands appear, a star pattern is formed. The Czochralski process of gem synthesis involves the melting of various elements in a platinum crucible. A small gem crystal (called a seed) attached to a rod is then dipped into the melt and slowly pulled away as the crystal grows around the seed. For this reason, the Czochralski method is also known as crystal pulling. Synthetic gems have the same chemical, optical, and physical properties of their natural counterparts, but are a more cost-effective alternative to a natural gem.
Light To Dark Red, Purple Red
Ruby-synthetic-star-czochralski classificationCommonNameRuby (Synthetic Star - Czochralski)SpeciesCorundumVarietyPulled Synthetic Star RubyColorsLight To Dark Red, Purple RedAlternateNamesLab Created Star RubyGemstoneGroupsKeySeparationsMagnification, RI and maybe fluorescenceClassificationCommentsStones typically have flat bases and are well cut calibrated cabochons. Stones will have brighter colors than natural rubies.
Ruby-synthetic-star-czochralski chemistry & crystallographyChemicalNamealuminum oxideChemicalFormulaAl2O3SynthesisCzochralski pulledCrystalSystemTrigonalChemistryClassificationOxideNatureSyntheticCrystallinityCrystallineChemistryComments
Ruby-synthetic-star-czochralski optical propertiesTransparencySemitransparent - OpaqueDispersionOpticalCommentsRefractiveIndex1.762-1.77
Tolerance:(+0.009/-0.005)Birefringence0.008-0.01OpticCharacterUniaxialOpticSignNegativePolariscopeReactionDoubly Refractive (DR)FluorescenceSWUV: strong red
LWUV: strong redCCFReactionPleochroismUnobservable
Ruby-synthetic-star-czochralski characteristic physical propertiesHardness9CharacteristicCommentsStreakWhiteSpecificGravity4.1-3.95 Typical:4ToughnessExcellentInclusionsPulled synthetic star ruby will have extremely fine needles that produce a slightly wavy natural looking 6-rayed star. The stones typically show low-relief curved striae or wavy growth. Sometimes bluish white smoke-like swirls and small round or distorted blackish gas bubbles are seen in stones.LusterSubAdamantineStabilityVery GoodFractureConchoidalCleavageNone