WASHINGTON — It hasn't been seen by the public in more than 50 years, it's about half the size of a golf ball and it's worth more than most CEOs make in a year.
The Wittelsbach-Graff Diamond, a sparkling 31.06-carat, deep-blue gem, is on display at the Smithsonian Museum of Natural History.
"It's probably the most famous diamond that the public has never seen," said Jeffrey Post, curator of the National Gem Collection at the museum.
The diamond, sold for $24 million two years ago, will be on display for the next six months alongside the Hope Diamond — the largest blue diamond in the world.
The two gems were brought together to determine if they had been cut from the same stone hundreds of years ago. After initial scientific tests, including microscopes and high-powered lights, Post revealed that the two are not cut from the same crystal.
"There is an uncanny resemblance, but they are different," he said, noting there was a possibility they came from the same region or mine in India. "They are not brothers and sisters, but perhaps distant cousins."
The dimly lit room where the diamonds are displayed had been secured and sealed. Armed guards slid open a heavy iron door and rolled in a cart with a petite box on top. Post and Laurence Graff, the owner of the Wittelsbach-Graff Diamond and chairman of Graff Diamonds International, lifted the silky blue box to reveal a shining diamond.
The brilliant blue gem's 82 facets glittered under the hot camera lights. Then it did something strange — it started to glow red.
Orange-red phosphorescence is a unique similarity of the Wittelsbach-Graff and Hope Diamonds. The phenomena occurs when blue diamonds are exposed to ultraviolet light, and testing conducted by Smithsonian researchers showed both display nearly identical spectral outputs.
Blue diamonds are rare and therefore carry a significant price tag on the open market.
In December 2008, Graff spent more than $24 million to obtain the gem, setting the record for the highest price paid at auction for a diamond.
"When I saw this stone I knew it was a stone we had to have," Graff said. "I had the opportunity to examine and value it in my own offices, and I came to the conclusion it was one of the rarest stones I'd ever seen."
Graff decided the diamond, which weighed 35.56 carats, needed to be re-cut and polished. He had three cutters work on the stone for more than a year, reducing it to slightly over 31 carats. Critics said the move diminished the historic integrity of the stone, which had been chipped over the course of its history.
But when Graff had it appraised, he said the value had gone up significantly.
"I decided that to create beauty, or acts of beauty, is not a sin. All we did was remove the blemishes, and now it is true perfection," Graff said.
The first record of the diamond's appearance was in 1664 when King Philip IV of Spain put it in the dowry for his daughter, Infanta Margarita Teresa, in preparation for her marriage to Emperor Leopold of Austria.
The stone acquired its name in 1772 when the Wittelsbach family of the House of Bavaria came into possession of the diamond. In 1807, it was set into the royal crown of Bavaria, where it stayed until 1918.
After World War I, Bavaria became a republic and the Wittelsbach Blue went up for sale in 1931 in London. The reserve price was not reached, and the diamond disappeared.
It turned up in 1958 at the Brussels World Exposition, where it was displayed without identification. In 1960, jeweler Jozef Komkommer was asked to re-cut the stone but recognized its historic significance and bought it instead. He sold it in 1964, and it disappeared into a private collection.
After the Smithsonian exhibit, the diamond's future is uncertain.
Graff said he might move it to London's Natural History Museum, but he also toyed with the idea of selling it.
"It's going to break my heart to sell it," he said, "But if you don't trade, you become a collector."