Synthetic Ruby Overgrowth On Natural Corundum Seed Gemstone & Information | Gemopedia by JTV | Gemopedia™
Synthetic refers to a man-made material with a natural counterpart that shares the same (or nearly identical) chemical, optical, and physical properties. Synthetic ruby may be created in a laboratory process that involves coating a natural corundum seed with feed material. During the process, a layer by layer grown occurs on the seed crystal.
Orangy Red, Red, Purplish Red
Synthetic-ruby-overgrowth-on-natural-corundum-seed classificationCommonNameSynthetic Ruby Overgrowth On Natural Corundum SeedSpeciesCorundumVarietySynthetic Ruby Overgrowth On Natural Corundum SeedColorsOrangy Red, Red, Purplish RedAlternateNamesGemstoneGroupsKeySeparationsmagnification with immersion and RI, birefringenceClassificationCommentsStones will have OTL RI where the chromium rich overgrowth layer remains.
Synthetic-ruby-overgrowth-on-natural-corundum-seed chemistry & crystallographyChemicalNamealuminum oxideChemicalFormulaAl2O3Synthesisovergrowth hydrothermalCrystalSystemTrigonalChemistryClassificationOxideNatureSyntheticCrystallinityCrystallineChemistryComments
Synthetic-ruby-overgrowth-on-natural-corundum-seed optical propertiesTransparencyTransparent - OpaqueDispersionStrength: moderate fire Value: 0.018OpticalCommentsRefractiveIndex1.762-0
Tolerance:(+0.009/-0.005)Birefringence0.008-0.01OpticCharacterUniaxialOpticSignNegativePolariscopeReactionDoubly Refractive (DR)FluorescenceSWUV: inert
LWUV: inert to weak redCCFReactionPleochroismUnobservable
Synthetic-ruby-overgrowth-on-natural-corundum-seed characteristic physical propertiesHardness9CharacteristicCommentsStreakSpecificGravity3.95-4.1 Typical:4ToughnessExcellentInclusionsColor on these stones is strong table up but patchy on the pavilion when viewed on a white piece of paper. The stones have wavy growth that can appear step like or crystalline. One might be able to see facet junctions of the original stone underneath the overgrowth layer that do not match the facets of the outer layer. Stones will probably show uneven color due to removal or the overgrowth layer. They have a mottled or roiled texture when stone is viewed with immersion.LusterSubAdamantineStabilityVery GoodFractureConchoidalCleavageNone