GemNotes

Stuller Embraces Digital Gemprint

Stuller Settings Inc., one of the largest U.S. jewelry manufacturers, now offers a registration certificate from Gemprint with every diamond of 3/8 ct. or larger.

Remember Gemprint? It’s the Toronto company that in the early 1980s developed a way to identify diamonds by capturing a laser-reflection pattern on Polaroid film. Now that these images can be stored digitally and readily retrieved on a personal computer, it’s far easier than it once was to match a wayward diamond with its recorded image.

New and improved. Those who have known Gemprint since its beginnings remember retaining a copy of the Polaroid and sending another copy to Gemprint for storage. A lost or stolen diamond, once found, could be photographed using a similar Gemprint machine, and this photo in turn could be used to trace the gem to its rightful source.

In theory it seemed like a clever idea. In practice, matching the photo to its identical counterpart among the thousands of photos in storage proved to be an arduous and sometimes futile effort. Still, Gemprint claims to have helped recover more than $1 million worth of stolen diamonds.

With digital reproduction, the idea is the same – photographing laser light reflections from within a gem – but the information is captured, stored, compared, matched, and retrieved in seconds. This information is shared instantly among a global network of jewelers and law-enforcement officials.

How does it work? The diamond is placed in the path of a laser beam. The laser reflections coming back from the diamond create a unique fingerprint-like pattern that’s digitally captured in the memory of a computer. Being able to capture this fingerprint quickly and accurately enables you to register gems being sold or taken in for repair and to control and track inventory. You keep this Gemprint on file in your personal computer or with Gemprint’s international database. No matter where a lost or stolen diamond is recovered, you can use this technology to match digital Gemprints and determine the provenance of the gem.

Laser inscription or Gemprint? No identification feature is fail-safe. Like laser inscription, a Gemprint can be altered if the diamond is repolished. But the benefit of using Gemprint is that it can’t be detected the way laser inscriptions can.

An observer can readily view laser inscriptions with a 10x loupe. That’s both good and bad. It’s good because an inscription can be easily identified by a jeweler, consumer, or law-enforcement officer. It’s bad because it can also be detected by a thief, who can have the inscription polished away. Since there’s no way for the thief to know that a diamond has been Gemprinted, the diamond is unlikely to be repolished. That’s a huge plus in the effort to recover stolen diamonds.

Gemprint sells its identification process to retail jewelers for about $15 per print. Stuller provides Gemprints for its loose diamonds for free. Gemprint spares jewelers the time and expense of laser inscription.The Gemological Institute of America, for example, charges $37 for a 15-letter/number inscription on a half-carat diamond. The International Gemmological Institute charges $54 for a seven-digit inscription.

A win-win situation. A Gemprint registration gives retail jewelers an additional selling tool and offers consumers an extra incentive to buy the product. As it is, Stuller already provides a number of useful sales tools. “We already give a diamond-grading analysis on our loose diamonds of 3/8 ct. and larger,” says Stuller spokesman Steve MacDiarmid. The company also offers proportion analysis using Sarin’s Dia-mension measurements and color-grading analysis using a Gran colorimeter.

Joe Buttross, vice president of Stuller’s diamond division, says he’s always been in favor of some kind of identification. The company considered laser inscription. Yet the costs are quite high if you do it in-house. It also takes a lot of time to develop the process. In fact, it may not be feasible anyway because of protected patents for laser inscription.

With Gemprint, Stuller can offer an identification feature right away, and do it in-house in a timely and cost-effective manner. A Gemprint can even lower a retail customer’s premiums on replacement insurance. Is it any wonder that Stuller likes Gemprint and sees it as a way to generate more sales?

Diamonds on the Ropes

New York’s Microcord hopes illusion will provide the key to the next jewelry phenomenon.

Since New York’s Microcord introduced its “floating diamonds” in February, Goldie Hawn has been photographed wearing them and Minnie Driver has sported them at trendy California eateries. Raquel Welch has some, and other women of style have been buying them in large numbers around New York and Los Angeles.

Why the fuss? “The diamonds appear to float on the wearer’s body,” says Microcord partner Scott Mesnick. “It’s really something to see.”

Because the diamonds must make an impact all by themselves, they must be very white, high-clarity, top-make goods, says Mesnick, who notes that every diamond is at least G or H color and SI1 clarity. “The 18k white gold bezel setting also gives the diamonds a much larger appearance.”

“Floating diamonds” are suspended on an ultrathin, high-tech cord that’s nearly invisible on the wearer. They can be worn singly, like a solitaire necklace, or grouped in tandem or in a pattern “to enhance the floating effect,” says Mesnick. He says the cord is extremely strong and can stand up to daily wear.

Mesnick won’t provide details on the industry from which his company adapted the cord – it might inspire copyists – but he does say it’s a “nylon composite monofilament with other compounds added to make it stronger.”

The diamonds range from .03 ct. to .40 ct. At $100 to $1,400 wholesale, they’re priced to sell quickly at quality volume retailers and jewelry chains, and Mesnick says they’ve done just that in recent weeks.

“We introduced them into Barney’s New York and they sold out within a week,” he says. “It was the same story at four locations of Saks.”

Microcord diamonds will be featured in the Neiman Marcus catalog and in top jewelry chains this fall, but Mesnick stresses he’s looking for “conservative growth.”

“We don’t want to rise quickly and fall. We know the product is hot, but we only want to grow fast enough to maintain our customer service – we have to be able to deliver on time.”

Knockoffs have already appeared. “What can we do?” says Mesnick. “We never expected to have 100% market share on this, but we do know that the most successful, quality-oriented stores buy the originals, and that’s what we’re aiming at.”

The company already has plans to add fancy shapes and colored diamonds and a line of earrings to its catalog.

– Russell Shor

Red Synthetics Are Coming

Red synthetic diamonds are likely to appear on the market soon, according to Ultimate Created Diamonds, a spin-off of the Russian Colored Stone Co., which has manufactured synthetic yellows for the last two years.

Company president Alex Grizenko says his Golden, Colo., firm is manufacturing 200 carats of red stones a month, which he will sell in polished form. He says most of the stones are in the half-carat to 1-ct. range, and their quality grades vary. The red color is achieved through irradiation.

So how do you do tell if a red diamond is lab-grown? Grizenko notes that most synthetics are attracted to powerful magnets. This is because the latest synthetic diamond manufacturing method involves a nickel-iron flux. If enough flux is present in the diamond, it can be picked up by a small but very strong neodymium magnet, available through many home electronics stores for only about $15.

But Grizenko adds that some synthetics might not be attracted to magnets, so any suspect stones are best sent to gem labs. Inclusion-free synthetic diamonds are usually identified by ultraviolet fluorescence and internal graining but might require more sophisticated testing. Since the gems are technically diamonds, they fool a thermal tester, the industry’s electronic pen commonly used for separating cubic zirconia from diamond.

Grizenko says he is developing the ability to make colorless synthetics but doesn’t envision marketing them soon.

Meanwhile, Tom Chat-ham of San Francisco-based Chatham Created Gems, the man who stunned the industry by declaring he would market colorless synthetic diamonds, says he hasn’t given up his hope of bringing them to the market. But he adds that, because of problems with his Russian partners, the project remains “stalled.” – Rob Bates

October Birthstones: Opal and Tourmaline

Lightning Ridge, New South Wales, Australia: A desert containing the world’s finest black opal. Piles of mine-discarded tailings, or “mullock heaps,” characterize the typical landscape of an opal-bearing region. Miners dig a hole and hope for good luck.

Not every month can boast two gem species as its birthstones. Those born in October can choose between opal and tourmaline.

Opal

A bad luck charm? Opal is reputed to bring bad luck. The fact is, unless your name is Hermione, it’s not bad luck at all, as the novel that spawned the myth, Anne of Gierstein by Sir Walter Scott, reveals. In that tale, Anne’s grandmother, Hermione, wearer of the mysterious opal, dies when the opal’s “flame” vanishes.

Hermione’s father, a Persian sorcerer, had given the opal to her as a good luck charm. It turned out to be more than that. The life of the opal was bound up with the life of Hermione, sparkling when she was happy, giving off red flashes when she was angry. At the christening of her daughter, a spiteful old widow hinted to Hermione’s husband, the Baron of Arnheim, that the opal had demonic powers. After dipping his finger in holy water, the baron deliberately splashed a drop onto the opal, quenching its radiance. Soon after, Hermione perished. So did the opal. Magical? Yes. Bad luck? No.

Play-of-color. We love opal for its “play-of-color,” a spectacular iridescence created from a highly unusual mineral structure.

The best way to describe opal is to start with its color background, which is typically white, black, gray, or orange. From here, we describe the pattern of color play, such as pinfire, flame, ribbon, or harlequin. We also describe its overall palette, such as “peacock” (mostly blues and greens) or “fire” (mostly reds and oranges).

Of the many varieties of opal, the ones most deserving mention are:

  • Black. All other aspects being equal, black is arguably the most valuable of all opals. It should have a very dark blue or gray background, with a generous display of play-of-color on top.

  • White. The variety most abundantly seen in jewelry is the white opal, a light “milky” gem with a blending of iridescent colors throughout.

Within the black and white opal categories are these play-of-color variations:

  • Pinpoint. Pinpoint or pinfire opal shows tiny flashes of iridescent colors.

  • Harlequin. Harlequin opal consists of numerous, sizable, interlocking, free-formed mosaic patches of play-of-color.

  • Flame. Fire-like colors of red, orange, or yellow are seen racing across the stone in streaks on a flame opal.

  • Boulder opal. A popular opal today, boulder opal is an almost colorless “crystal” gem containing play-of-color, all seamed within cracks and cavities of a coppertoned host rock called iron-stone. Boulder opal is commonly called Queensland opal.

  • Yowah nut. This small, egg-shaped boulder opal shows its play-of-color when its iron-stone shell is opened.

  • Fire opal. This common opal usually shows little or no play-of-color. Commonly called Mexican opal, this gem typically appears semi-transparent and orange.

Some unusual opals have been created in the fossilization of bones, seashells, bamboo, and trees. They become valuable when their play-of-color is apparent.

The most important spectral colors seen in opal are red, orange, yellow, purple, blue, and green. The consistency of these colors, the evenness of background, and the brightness of color play are what make opal beautiful and valuable.

Gemologically speaking. Opal is a sedimentary material of silica spheres. It occurs in layers between matrix host rock, and when the spheres are relatively consistent, the passing light creates iridescent colors. Because of its sedimentary formation, it is neither hard nor tough. For this reason, most opals are polished en cabochon. Thickness is retained for strength.

Because opal is found in thin sedimentary seams, it’s not uncommon to come across an opal doublet (a thin layer of opal capped by a rock crystal quartz cabochon) or a triplet (a layer of black chalcedony, topped by a thin, flat seam of opal, which in turn is capped by rock crystal). These additions give the fragile opal a strength it otherwise wouldn’t have.

Localities. Opal is typically found in the Australian outback. Opal mining is sometimes a matter of luck. On the surface, you see flat deserts of open countryside. Dig a hole in known deposit areas, and you might hit pay dirt.

Some famous sandstone areas of opal mining in Australia are Yowah in Queensland; Lightning Ridge and White Cliffs in New South Wales; and Mintabee, Coober Pedy, and Andamooka in South Australia.

Enhancements, synthetics, imitations. Enhancements are common. Most often it’s a matter of changing white opal with only slightly visible play-of-color to black opal showing obvious play-of-color. To do this, the opal is either “smoked” or “sugared.” Smoke treatment of opal is rarely done these days. Sugar treatment involves soaking the gem in a sugar solution and then an acid solution that carbonizes the sugar. Both enhancements introduce a dark substance into the porous opal’s top layers. This substance contrasts with the opal’s milky body color, so that the originally not-so-apparent iridescent colors now stand out.

The latest enhancement, polymer impregnation, is used to enhance colors in both white and black opal. It’s almost impossible to detect without sophisticated testing equipment.

There are also some fine-quality synthetic and imitation opals. You can identify the synthetic material by magnification. Look for a consistent, small, honeycombed structure, sometimes referred to as “snakeskin.” The plastic imitations look quite good but can be identified by heft (they’re lighter than opal) and hardness (they’re softer than opal).

Cost. Prices vary according to background color and play-of-color. Fine-quality black opals of 1 to 10 cts. with red play-of-color can cost between $2,000 and $4,000 per carat, while those with green-blue play-of-color fetch between $600 and $1,500 per carat. Boulder opal of 5 to 10 cts. can cost $1,500 to $6,000 per carat, while fine white opals of the same size cost only $45 to $85 per carat. Round fine opal triplets of 7 mm generally cost $15 apiece.

Tourmaline

What color would you like? Tourmaline is the other October birthstone. Pink tourmaline is the designated variety. But since tourmalines come in so many colors, sometimes even two or three in the same gem, many jewelers promote them all as October’s birthstone.

Localities. The most important locality for tourmaline buyers in the United States is Southern California. The Pala Indian Reservation in the Mesa Grande region of San Diego County, about 20 miles inland from Carlsbad (the Gemological Institute of America’s new home town), has some of the most important tourmaline mines. Pala International, owned by geologist Bill Larson, has been mining the reservation area over the past few decades, producing some of the finest pinks and bicolors (typically pink and green), watermelons (green on the outside, pink inside), and even tricolors (blue, green, and pink). Even so, with so little recent production at the “Himalaya” mine – the most active mine of the last 10 years – all commercial mining in California has been put on hold.

There are also tourmaline deposits in Maine. Gem-quality crystals are found chiefly in the region between the Auburn-Poland area and Oxford County, a 15-mile stretch running through the southwestern portion of the state. One of the more recent and important green crystals is one measuring 10 in. tall called the “Jolly Green Giant.” This region is nowhere near the level of past production in Southern California. Yet, mineral collectors still find an occasional gem crystal – including pink, green, indicolite (blue tourmaline), and watermelon – in places such as the Dunton Mine, Mount Mica, or Black Mountain regions.

Outside the United States, Brazil has by far the most productive tourmaline deposits. The country is famous for the most important of all gem tourmalines, the “electric” blue and green Paraíbas. These were discovered in the 1980s. They crystallize with an unusually large amount of trace minerals, copper and manganese. While much of the gem material appears to have a naturally vibrant color, stones with less-obvious colors can be enhanced by heat treatment. Currently, production is said to be “limited” with no formal mining taking place. “Cat’s-eye” tourmaline also comes from Brazil.

Other important localities for tourmalines include Sri Lanka, Madagascar, Afghanistan (known for its deep purple- pink “fuchsia”-colored, heat-treated gems), and Tanzania (with its chrome greens).

Gemologically speaking. With a hardness of 7 to 71/2 and very good durability, tourmalines are a highly wearable gem. One curious note pertains to tourmaline’s electrical quality. For centuries, tourmaline has been known to possess an electric charge generated by heat (pyroelectricity).

Jewelers will notice that tourmalines tend to collect dust in warm showcases and window displays. Be careful to rinse off any dust before wiping the gem clean, since dust contains particles of quartz (hardness of 7) and could scratch tourmaline’s surface.

Cost. Prices vary. The most expensive are the Paraíbas, at roughly $2,500 per carat for fine-quality stones of 1 to 2 cts. Chrome tourmaline cannot compare to Paraíba. Even so, this more common tourmaline is still fairly pricey ($200 to $350 per carat), since the chromium adds depth and saturation to the gem’s color. Afghanistan tourmaline goes for $200 to $300 per carat, while fine green gems cost $40 to $60 per carat.

Astrology. For Libras, those born from Sept. 22 through Oct. 22, the astrological gem is peridot. For Scorpios, born from Oct. 23 through Nov. 21, beryl (emerald, aquamarine, etc.) is the astrological gem.