5 Things To Know About … Sphene

Discover what gives the gem a fire that can out-sparkle a diamond, its second name, geographic origins, and more.

Brecken Branstrator brecken.branstrator@nationaljeweler.com

A 17.49-carat sphene cut by Roger Dery

Sphene is one of those magical gems that can really enchant you—the best faceted examples display brilliant fire and flash three different colors.

I, for one, love when the gemstone is a vibrant, almost lime green that also shows flashes of orange and yellow.

Sphene belongs to the titanite mineral group, occurring as an accessory mineral in granitic and calcium-rich metamorphic rocks, and is the only member of the group commonly used in jewelry.

Here are five things to know about this unique gemstone.

1. It has another name.

Sphene comes from the Greek word “sphenos,” meaning wedge, a reference to the mineral’s characteristic wedge-shaped crystals.

But it also goes by the name titanite, referencing its place in the mineral group.

According to many online sources, “sphene” is more commonly used in the gem and jewelry sector while geologists and mineralogists tend to use “titanite.”

2. Gem-quality examples are rare.

Sphene is a collector’s gem and is particularly rare when you start talking about a clean stone above 5 carats, the International Gem Society says.

As is the case with all gemstones, size creates a premium with this species.

3. It has more “fire” than a diamond.

Sphene has one of the highest dispersions of any mineral; the term dispersion refers to a mineral’s ability to break white light into spectral colors.

The dispersion of sphene is 0.051. A diamond’s dispersion, by comparison, is 0.044.

It’s this high number that helps to give the stone such an intense “fire,” showcasing multiple colors, especially when it’s well-cut.

Sphene has a refractive index of 1.843-2.110 and a birefringence of 0.100-0.192. Its high birefringence often results in visible doubling of facets within the stone, meaning there looks to be a “fuzziness” inside the gem.

It’s a 5 to 5.5 on the Mohs scale, making it softer than other, more well-known gems like sapphire, ruby and even garnet.

Sphene has distinct cleavage in one direction, but can still create beautiful jewelry when cut and set properly.

It’s also pleochroic, showing more than one color depending on the angle from which you view it; sphene’s transparent specimens are notable for their trichroism, showing three different colors.

The three colors depend on the base stone color, according to Gemdat.org.

A 24.75-carat pear-shaped sphene from Mayer & Watt

4. It comes in a variety of hues, but some are preferred.

Sphene’s typical color range is yellow, green, orange and brown. There are also pinks and reds, which are rarer, as well as some black and colorless material.

According to IGS, there’s a preference in the market for lighter tones, especially the yellows, light oranges and greens, which best show off the gemstone’s amazing dispersion.

IGS also notes that “chrome sphene”—dark green in color—is the most valuable type as its hue mimics a good emerald.

5. Here are its sources.

The primary sources of sphene are Canada, Madagascar and Mexico, IGS says.

Baja California, Mexico produces yellow-brown, brown, green and dark green (chrome) crystals up to 4 inches long, making it one of the world’s main sphene deposits.

Madagascar produces green crystals, some of which are large in size, while Canada produces brown and black crystals.

IGS added that Austria and Switzerland also have both produced sphene.

Other places where sphene has been found are: India, Sri Lanka, Afghanistan, Germany, Kenya, Myanmar, Pakistan, Russia, New York state and Minas Gerais, Brazil.

   
  
 


 
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Brecken Branstratoris the senior editor, gemstones at National Jeweler, covering sourcing, pricing and other developments in the colored stone sector.

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