'Incomparable' diamond highlights Carnegie Gem and Mineral Show

It's understandable if Dan Lagiovane, spokesman for the Carnegie Museum of Natural History, won't supply the security details of housing the world's largest internally flawless diamond and third largest polished diamond for four days in Pittsburgh.

It's also fairly clear why Julie Currier, public relations manager for Bailey Banks and Biddle jewelers, won't reveal the logistics of transporting its exclusive gemstone -- it's 10 times larger than the Hope Diamond, with a current market value of $25 million -- from an unrevealed site.

Generating all the maximum-security precautions of a presidential visit and the intrigue of an Indiana Jones adventure, the majestic 407.48-carat "Incomparable" diamond will make a rare appearance at the sixth annual Carnegie Gem and Mineral Show, which begins Thursday with a gala.

"It's very rarely seen because of the security needed to protect it," Currier says of the diamond. "It's being brought to Pittsburgh through a very secure network from a private vault in an undisclosed U.S. location." Two armed guards will be on duty 24 hours a day at the museum during its stay, she says, in addition to the museum's own heightened security measures, about which Lagiovane won't discuss specifics.

"I'd rather not comment for obvious reasons," he says. "All I can say is we are taking special precautions."

For only the fifth time in its history, "The Incomparable" diamond will be placed on temporary exhibit in a museum. Discovered in the town of Mbuji Mayi in the Democratic Republic of Congo during the 1980s, it weighed 890 carats in its rough state, making it the fourth largest rough, uncut diamond ever found.

At the Carnegie display in the Founder's Room, "The Incomparable" will be surrounded in its showcase suite by 14 satellite diamonds that were produced when the rough diamond was cut, Currier says. Those stones range in size from 15.66 to 1.33 carats.

Sharing space in the Founder's Room will be four pedestal glass cases with fiber-optic lighting containing a collection of some "unbelievable" diamond jewelry by diamantaire-manufacturer Julius Klein Group, a global company that sells to high-end retail clients with offices in Los Angeles, New York and Tel Aviv, according to spokeswoman Brandee Dallow in New York.

She says highlights of the collection -- available for sale -- include a 50-carat fancy orange-pink cushion cut diamond ring, a 35.6-carat emerald cut flawless diamond ring, a 79-carat yellow radiant cut diamond necklace, and a 90-carat diamond necklace featuring a 14.46-carat D-color (colorless) lozenge-cut diamond. Ballow estimates the current market value of the entire collection at more than $15 million.

In addition to these spectacular jewelry items and gemstones, some 37 international vendors -- 10 more than last year's show -- will offer crystals, precious gems and minerals, rare colored stones, lapidary art and holiday gifts, many in a moderate priced range, says Debra Wilson, collections assistant for Carnegie Museum's Section of Minerals.

Moses Jewelers of Butler will offer a collection of pink and blue diamonds, along with natural black opals, and fine antique and period jewelry. Tim Moses, one of the principal owners with his father, Merril Moses, and brother, Larry Moses, says his company is one of the few local dealers offering the rare colored diamonds.

Blue diamonds are extremely hard to find, Tim Moses says, originating almost exclusively in Africa. He will be bringing at least three for purchase, valued at $500 up to $250,000. Moses attributes the current wave of popularity of colored diamonds to celebrities such as Jennifer Lopez who have been seen wearing the stones as engagement rings.

World-renowned gem artist Helen Serras-Herman is creating a special piece for the show -- a necklace featuring a Herkimer diamond, stunning black diamonds and black lava beads from the Canary Islands. Jose Vesga Minerals of Colombia will bring an exceptional collection of diamonds, emeralds and handcrafted jewelry by young Colombian designers.

The Carnegie's own Hillman Hall of Minerals and Gems will offer more than 350 minerals to view, grouped according to their chemical composition, Wilson says. In addition, more than 300 cut and uncut gems are part of a temporary exhibit, "India: Land of Zeolites."

Six invited museum exhibitors -- including Penn State University and Houston Museum of Natural Science -- will have on display some of the world's finest mineral specimens, she says. A special children's activities area will provide gem panning, crafts, demonstrations and a "pick your own" geode, rocks and minerals.

Kicking off the Carnegie Gem and Mineral Show will be "Diamond Dazzler," a gala fund-raiser and preview celebration Thursday. Included will be a catered reception.

A Benefit Mineral Auction will be at 7 p.m. Nov. 22, featuring specimens from the collections of the Carnegie Museum of Natural History, the Houston Museum of Natural Science, the Seaman Mineralogical Museum and the Harvard Mineralogical Museum.

A young girl playing outside her uncle's house in the town of Mbuji Mayi in the Democratic Republic of Congo is said to have found the "Incomparable" stone near a diamond mine in a pile of rubble, according to the Carnegie Museum of Natural History.

She gave the diamond to her uncle, who sold it to some local African diamond dealers. It was then involved in several transactions, including a group of Lebanese buyers operating out of Kinshasa, and a senior buyer for De Beers, who bought it in Antwerp. Sir Philip Oppenheimer, then president of the Central Selling Organization and a De Beers director, subsequently sold it to Donald Zale, chairman of the board of the Zale Corp., a Dallas-based jewelry store chain. Zale purchased the diamond in partnership with Marvin Samuels of the Premier Gems Corp. and Louis Glick, both prominent figures in the New York diamond industry.

In November 1984, the stone was unveiled as part of Zale Corp.'s 75th anniversary. Shortly afterward, it was put on display at the Natural History wing of the Smithsonian Institution in Washington, D.C.

The diamond cutting took place in 1988 following three years of intensive research, examination and planning by co-owner Marvin Samuels and accomplished diamond cutters Jacques Swabb and Hy Kessler of New York. Their efforts produced a 407.48-carat, fancy yellow, internally flawless diamond, which has been graded by the Gem Trade Laboratory Inc. as a shield-shaped step cut, internally flawless clarity and fancy brownish-yellow in color.

To maximize the rare stone's size and beauty, "The Incomparable" was cut in a modified pear-shape, step-cut design ("triolette"). Measuring 53.90 millimeters by 35.19 millimeters by 28.18 millimeters, it is now classified as the third-largest polished diamond in the world behind the Golden Jubilee, which weighs 545.67 carats, and the Cullinan I, which weighs 530.20 carats.

In October 1988, "The Incomparable" appeared at auction in Christie's New York as the largest diamond ever offered to the public for sale. It was hoped the diamond would bring in $20 million, but it was withdrawn from sale when the top bid was only $12 million -- the highest price ever bid at auction for a single stone at that time. Zale Corp., Premier Gem Corp. and Louis Glick Co. still own the stone.

Besides being exhibited in both its rough and polished forms in the Smithsonian Institution's Hall of Gems and Minerals at the Museum of Natural History, the stone has been shown in exhibits at The American Museum of Natural History in New York, San Diego Natural History Museum and the National Science Museum in Tokyo. The Carnegie Gem and Mineral Show marks the diamond's first appearance in the tri-state area.

Additional Information:

Show Info

Sixth annual Carnegie Gem and Mineral Show at Carnegie Museum of Natural History

When : Nov. 21 through 23. Hours: 10 a.m. to 6 p.m. Nov. 21, 10 a.m. to 5 p.m. Nov. 22 and noon to 5 p.m. Nov. 23. Gala preview party, 7 to 10 p.m. Thursday

Admission : Free with general admission to the museum: $8; $5 for senior citizens, children age 3 and older and full-time students with ID. $125 for preview party

Where : 4400 Forbes Ave., Oakland.

Details : (412) 622-3131 or carnegiemuseums.org . (412) 622-3232 for gala preview party