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    1. Sphene (Titanite) Value, Price, and Jewelry Information

      Fine yellowish green emerald-cut sphene (Madagascar), displaying lots of dispersion and the doubling of back facets characteristic of this gemstone. 2.47 cts, 9.3 ? 6.8 ? 4.5 mm. ? All That Glitters. Used with permission.

      Sphene (Titanite)

      Sphene, also known as titanite, has rich body colors, strong trichroism, and a fire that exceeds diamond. Although softer than many more popular gems, sphenes can make wonderful jewelry stones if set and maintained properly.

      Sphene (Titanite) Value

      As with many gemstones, color, clarity, and carat are the most important value factors, followed by the skill and artistry shown in cutting. A preference exists for lighter tones, especially yellows, light oranges, and greens, which best exhibit sphene’s magnificent dispersion.

      Chrome sphene is the most valuable type. The chrome sphene from Baja California is the color of fine emerald and very rare, especially if clean and larger than 1 carat. Brazilian yellow gem material has a sleepy look and isn’t as bright as that from Baja. Some of the largest and most spectacular green gems have been cut from Indian material.

      Sphene is usually included and rarely even eye clean.

      Size is definitely a premium characteristic with this species.

      In general, specimens with reasonably good clarity, strong and attractive body color, and at least some display of dispersion command the best prices.

      chrome sphene

      “Chrome Sphene,” 10.79 cts. ? ARK Rare Gems. Used with permission.

      The International Gem Society (IGS) has a list of businesses offering gemstone appraisal services.

      Titanite Value via Gem Price Guide

      Accompanying value information:
      Faceted .5 to 1 carats 1 to 10 carats 10 to 20 carats
      to /ct to /ct to /ct

      Sphene (Titanite) Information

      Data Value
      Name Sphene (Titanite)
      Varieties Strontium Titanate
      Colors Colorless, yellow, green, gray, brown, blue, rose red, black. Often zoned. Color correlates with Fe content: green and yellow due to low Fe; brown and black due to high Fe.
      Crystallography Monoclinic. Crystals often wedge shaped, well formed, flattened, prismatic; also massive, compact.
      Refractive Index 1.843-2.110
      Luster Resinous to adamantine.
      Polish Luster Adamantine (difficult to polish).
      Hardness 5-5.5
      Wearability Poor
      Fracture Conchoidal
      Specific Gravity 3.45-3.55. (See "Identifying Characteristics" below).
      Birefringence 0.100-0.192. (See "Identifying Characteristics" below).
      Cleavage Distinct 1 direction
      Dispersion 0.051 (strong)
      Heat Sensitivity Yes
      Luminescence None.
      Luminescence Present No
      Enhancements Heating.
      Transparency Transparent to opaque.
      Absorption Spectrum Sometimes see "didymium" or rare earth spectrum. This is especially distinctive in Sri Lankan gems (sharp lines at 5860, 5820, 5300, and others).
      Phenomena Color change (very rare).
      Formula

      CaTiSiO5.

      Pleochroism

      Moderate to strong.

      • a?= pale yellow; β?= brownish yellow; γ?= orange-brown.
      • Sometimes (blue crystals): colorless/blue.
      Optics

      a = 1.843-1.950; β = 1.870-2.034; γ = 1.943-2.110.?Biaxial (+), 2V = 17-40°; lower indices with lower Ti content. (See “Identifying Characteristics” below).

      Optic Sign Biaxial +
      Etymology

      From the Greek sphenos for “wedge,” in allusion to sphene’s characteristic wedge-shaped crystals. Titanite refers to its titanium content.

      Occurrence

      Sphene occurs as an accessory mineral in igneous rocks, and in metamorphic rocks such as schist and granite, often in fine crystals.

      Inclusions

      Feathers, crystals, needles, fingerprints, zoning.

      Faceted Sphene Collection 208

      Sphene: Madagascar (6.22), Baja California, Mexico (1.55, 1.76) India (7.01) // Baja California, Mexico (1.01, 1.44, 4.22), India (2.65). Photo ? Joel E. Arem, PhD, FGA. Used with permission.

      Comments

      Sphene or titanite belongs to the titanite mineral group as the titanium-rich (Ti) member. It’s the only member of this group commonly used as a gemstone. While mineralogists officially use the term titanite to refer to this stone, many gemologists use the term sphene. By either name, however, these striking gems remain little known to most jewelry connoisseurs, despite reasonable availability.

      Sphene’s relatively low hardness (5 to 5.5) and distinct cleavage make it a risky choice for jewelry. However, it also possesses gemological properties that make it a desirable piece for collectors as well as adventurous jewelry enthusiasts.

      Sphenes frequently come in yellow, orange, brown, and green hues, with many gradations between them, and often show color zoning. Iron (Fe) and rare-earth element impurities create these typical colors. Chromium (Cr) colors the rare “chrome sphene” variety an intense green. Sphenes can also occur colorless, red, blue, black, and brown.

      Sphene’s dispersion or fire ranks among the highest in the gem world. However, its body color, degree of inclusions, cutting orientation, and cutting style may enhance or obscure this feature. (Gems with high dispersion and strong pleochroism like sphene may not show both properties at the same time).

      Sphene - Pakistan - Various Cuts

      Three fine sphenes (Pakistan) showing high dispersion. Small trilliant: 1.95 cts; cushion: 1.56 cts; large triangle: 2.78 cts, approx 9.9 ? 8.9 ? 5.4 mm. ? All That Glitters. Used with permission.

      If polished well, sphenes can match diamond’s adamantine luster. Unfortunately, polishing this gem well proves quite difficult.

      Round brilliant cuts can showcase sphenes beautifully. However, almost any cut designed for a zircon will also look wonderful.

      “Bowesite,” an ornamental rock from Australia, may contain sphene and other gem materials.

      Identifying Characteristics

      Variations in Sphene Properties by Locality

      Locality ?a

      Birefringence

      Specific Gravity

      Madagascar

      1.910

      2.070

      0.160

      3.52

      Mexico

      1.908

      2.080

      0.181

      3.53

      Sri Lanka

      1.909

      2.099

      0.190

      3.52

      Brazil

      1.911

      3.53

      Sphene Gems - Baja California - 206

      Sphene: Baja California, Mexico (6.0, 6.4, 6.75). Photo ? Joel E. Arem, PhD, FGA. Used with permission.

      Refractive Index

      Sphene’s refractive indices (RI) exceeds 1.81. Therefore, its refractometer readings will be “over the limit” (OTL), since that exceeds the RI of most commercial RI liquids.

      Pleochroism

      Birefringence

      Sphene’s high birefringence usually results in some visible doubling of facet images within the stone. This causes a degree of internal fuzziness similar to that often seen in zircon or peridot.

      sphene - Pakistan

      “Sphene,” 14.75 cts, Pakistan. ? ARK Rare Gems. Used with permission.

      Color Change

      Some rare specimens from Afghanistan and Pakistan have demonstrated color change. Vanadium-bearing sphenes have shown green to yellow-green in daylight but brownish orange to brown under incandescent light. Another specimen has shown a brownish, yellowish green in daylight but orangey yellow under incandescent light.

      Synthetics

      Laboratories have synthesized sphene or titanite for research in geology, pigments, and radioactive waste disposal. Synthetic crystals have been created. However, there is no known use of synthetic sphenes as jewelry stones. (This beautiful but brittle, little-known gem doesn’t currently generate a market for synthetics).

      Because of its high dispersion and luster, colored cubic zirconia (CZ) can make a convincing sphene simulant. However, CZ lacks sphene’s birefringence and surpasses its hardness. CZ also fluoresces under ultraviolet light, while sphene doesn’t.

      Brownish red to orange gems such as grossular garnets, zircons, and rare bastn?sites have been misidentified as sphenes (and vice versa).

      Beware of chrome sphene sold as “Mexican Emerald.” Sphenes and real emeralds have very different properties and prices. Unfortunately, disreputable vendors sometimes attach the name of a more popular and expensive gem to a different gem just to drive up its price. For more examples, see our list of false or misleading gemstone names.

      Enhancements

      Heating can turn sphenes orange or red.

      Sources

      Canada, Madagascar, and Mexico are the primary sources of this gemstone. Baja California, Mexico produces yellow-brown, brown, green, and dark green (chrome) gemmy crystals up to 4 inches. This may be one of the world’s major sphene deposits. Madagascar produces green crystals, sometimes large. Canada produces brown and black crystals.

      round sphene - Madagascar

      Round Sphene, 3.42 cts, 9.1 ? 5.9 mm, green, Madagascar. ? ARK Rare Gems. Used with permission.

      Historically, Zillerthal, Austria and Grisons, Switzerland both produced gems.

      Other notable gem-quality sources include:

      titanite (sphene) - Canada

      “Titanite,” 2.5 cm, Millar’s Mine, Tory Hill, Monmouth Township, Haliburton County, Ontario, Canada, by Kelly Nash. Licensed under CC By 3.0.

      Stone Sizes

      Very rare in clean stones over 5-10 carats, even a 5-carat flawless sphene would make a rare, fine stone.

      Indian material generally cuts to about 10 carats, Madagascar material to perhaps 15 carats.

      Brazilian yellow stones over 5 carats are scarce. Sri Lankan gems generally range under 10 carats.

      Myanmar has produced stones over 20 carats. However, Mexico has the potential to produce some of the largest faceted gems.

      sphene - Brazil

      “Sphene (Titanite),” twinned, Campo do Boa Mine, Capelinha, Minas Gerais, Brazil, 9.3 ? 5.8 ? 0.7 cm. ? Rob Lavinsky, www.iRocks.com. Used with permission.

      Care

      If placed in protective settings and worn just occasionally, sphenes can make a spectacular addition to your jewelry collection. However, shield these gems from impacts, scratches, heat, and acids (including sweat). Never use mechanical cleaning systems such as steamers or ultrasonics. Clean sphenes only with a soft brush, mild detergent, and warm water. See our Gemstone Jewelry Cleaning Guide for more recommendations.

      heat-cut sphene - Sri Lanka

      Heart-shaped Sphene, 2.57 cts, 9.5 ? 7.0 ? 4.9 mm, yellow gold, Sri Lanka. ? ARK Rare Gems. Used with permission.

      by Joel E. Arem, Ph.D., FGA, Barbara Smigel, PhD. GG, L. Allen Brown, International Gem Society

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