Smithsonian.com

Laurence Graff with Wittelsbach-Graff Diamond. Photo by David X Prutting @ Patrick McMullan.

Last month, the National Museum of Natural History announced that rarely-seen, Wittelsbach-Graff Diamond would be temporarily joining the Hope Diamond in the museum’s gem collection. Tomorrow, that diamond goes on display.

“It is a truly remarkable opportunity,” said Cristián Samper, the museum’s director, at this morning’s press preview, “to have two of the great blue diamonds of the world together in the same museum.”

Standing alongside him were Laurence Graff, chairman of Graff Diamonds International Ltd. and owner of the gem, and Jeffrey Post, curator of the Natural History museum’s National Gem Collection. The three rolled a cart out and peeled back a blue cloth to reveal the glistening, 31.06-carat diamond, perched atop a cylindrical case.

The Wittelsbach-Graff Diamond passed through many hands to get to where it is today. Philip IV of Spain originally gifted it to his daughter, the Infanta Margarita Teresea, in 1664, when she was engaged to Emperor Leopold I of Austria. It switched hands to the Wittelsbachs, members of the ruling House of Bavaria, in 1722. Then, in 1931, a glass knockoff thought to be the actual diamond was sold at a Christie’s auction. The real one turned up in Belgium in 1951 and appeared at the Brussels World’s Fair in 1958. (It hasn’t been on public display since.)

Museum Director Cristián Samper (left), Laurence Graff (center) and National Gem Collection Curator Dr. Jeffrey Post (right) introduce the Wittelsbach-Graff Diamond. Photo courtesy of Smithsonian Institution, Chip Clark.

Graff purchased the diamond for $24.3 million at an auction in London in December 2008. At that time, the stone was chipped and blemished, but Graff was confident in the skill of his craftsmen, who repolished it. The Gemological Institute of America assessed the diamond after the work was completed and declared it “the largest Flawless or Internally flawless, Fancy Deep Blue, Natural Color we have graded to date.”

Post explained that it is trace amounts of the element Boron that gives the diamond, “one of the earth’s rarest creations,” its blue color. In the hundreds of years of diamond mining, he adds, the Hope and Wittelsbach-Graff Diamonds stand in a class of their own. The geologist was particularly thankful for the opportunity to study both diamonds side-by-side, which he did along with other experts just last week. It is widely accepted that both diamonds are from the Kollur mine in India’s Golconda District. Some even speculated, given their similar steely blue color, that they were cut from the same original diamond. But Post and his colleagues have solved the mystery once and for all. “They are not brother and sister, but perhaps distant cousins,” he concluded.

Graff wondered aloud about the romantic and mysterious stories the stone might play a part in over the next thousand years. He picked up the diamond, ever so carefully, and rested it on the back of his hand, as if it were a ring. ”It’s an incredible feeling to be holding the world’s most valuable diamond,” he said.

The Wittelsbach-Graff Diamond will be on display in the Harry Winston Gallery, on the museum’s second floor, beginning tomorrow, January 29 through August 1, 2010.