Professional Jeweler Archive: Bright Light, Benitoite

September 2002

Gemstones & Pearls/News

Bright Light, Benitoite

A new venture mining California's rare state gem has a plan to make it more recognizable and available

The gem benitoite comes in eye-catching shades of cornflower blue, is fully natural and all-American, and is the longtime state gem of California. It’s never become a mainstream gem, however, because it’s quite rare and tends to be small, so it’s generally faceted to save weight rather than to bring out optical advantages. That may change.

A joint venture between Iteco of Powell, OH, and Collector’s Edge Minerals of Golden, CO, aims to boost production and make benitoite more well-known. “Fifty to 70% of the value in benitoite has been in smaller goods (0.07-0.49 carat),” says Iteco President Paul Cory, who is responsible mostly for marketing and distributing faceted benitoite. “We now have significant inventoried quantities of round faceted material in the 1.5mm-4mm range, in white to graduated tones of blue.” That’s welcome news for jewelry manufacturers, who have shied away from benitoite in the past because of unreliable supplies.

Cory also says he’s focused on cutting the gem for optical perfection, not to save weight. Award-winning cutter Skip Franklin of Powell, OH, cuts the larger stones; smaller ones are cut to standard sizes in Thailand.

The Source

The gems that Cory markets come from the Benitoite Gem Mine, which Brian Lees of Collectors Edge Minerals bought in early 2001 from Buzz Gray and Bill Forrest, who had operated it 35 years. (AZCO, a large-scale miner, leased the mine four years ago but later withdrew.)

Benitoite is mostly violet-blue to blue, though colorless and extremely rare pink stones have been found. It has a fiery dispersion of .044 and an adamantine luster when polished, just like diamond. Unlike diamond, however, benitoite is doubly refractive, has strong pleochroism and ranks 6 to 6.5 on the Mohs hardness scale. Still, when benitoite is cut to best return light and color, even some diamantaires have thought it to be diamond.

Benitoite enthusiasts say the gem doesn’t need to stand on any similarity to diamond. They note its own features, including an interesting history. Credit for the discovery of benitoite goes to copper prospectors Jim Couch and L.B. Hawkins. After riding horses for days in search of minerals in the winter of 1907, they saw bluish glimmers at the bottom of a rushing stream and weathered crystals scattered on nearby hillsides. George Louderback, a mineralogy professor at Berkeley, CA, determined the mineral to be a new species and named it benitoite, after San Benito County, CA, the only known source.

If Lees and Cory have their way, the bluish glimmer that attracted admirers a century ago will now do the same on a consistent basis from jewelry counters.

• Iteco Inc., Powell, OH; (614) 923-0080.

– by Robert Weldon, G.G.

Fine, large benitoites are being faceted for best light return and color. This grouping was cut by Skip Franklin of Powell, OH.

Photo by Robert Weldon.

Iteco is betting on melee of different shades to help drive the engine of benitoite’s future. Seen here are colorless to light blue to dark violet blue gems ranging from 0.07 to 0.15 carat.

Photo by Robert Weldon.

Copyright © 2002 by Bond Communications