Sphene Gemstone & Information | Gemopedia by JTV | Gemopedia™
A brilliantly transparent gem, sphene has fire greater than that of diamond! This gem is named from the Greek word for "wedge," as its crystals are typically wedge shaped, but may be referred to by its mineral name, titanite. On rare instances, sphene may be pink, brown or black in color, but is mainly found in a range of green to yellowish green colors. Another characteristic sphene possesses is birefringence, or double refraction, meaning that light splits into two rays as it passes through the gem. As a result, the back facets appear as double images, giving the gem a soft, hazy appearance, similar to the doubling seen in zircon.
Yellow, Green, Brown, Orange, Red
Sphene classificationCommonNameSpheneSpeciesSpheneVarietyColorsYellow, Green, Brown, Orange, RedAlternateNamesTitanite, Chrome SpheneGemstoneGroupsKeySeparationsOTL RI reading, very strong eye visible doubling, possibly spectraClassificationCommentsChrome sphene is intense green in color.
Sphene chemistry & crystallographyChemicalNamecalcium titanium silicateChemicalFormulaCaTiSiO5SynthesisCrystalSystemMonoclinicChemistryClassificationSilicateNatureNaturalCrystallinityCrystallineChemistryComments
Sphene optical propertiesTransparencyTransparent - TranslucentDispersionStrength: strong fire Value: 0.051OpticalCommentsRefractiveIndexOver The Limit 1.9-2.034
Tolerance:(+0.020/-0.020)Birefringence0.1-0.135OpticCharacterBiaxialOpticSignPositivePolariscopeReactionDoubly Refractive (DR)FluorescenceSWUV: Inert
LWUV: InertCCFReactionPleochroismTrichroic, (in green gems) strong greenish yellow, yellow to brown, and colorless; (in brown gems) strong yellow, reddish-orange, and brownish yellow and brownish orange, (in yellow gems) moderate to strong greenish yellow, brownish-orange, and colorless
Sphene characteristic physical propertiesHardness5-5.5CharacteristicCommentsStreakWhiteSpecificGravity3.5-3.54 Typical:3.52ToughnessVariesInclusionsSphene occasionally contain tiny crystals that aline in straight rows or "feathers", natural inclusions, actinolite needles and twinning is common. Stones have strong dispersion and eye-visible doubling.LusterSubAdamantineStabilityFractureConchoidal, SplinteryCleavageGood, in one direction