Smithsonian finds Hope and Wittelsbach-Graff diamonds are not from same stone

The Wittelsbach-Graff Diamond will be on display for first time in 50 years at the National Museum of Natural History.
The Wittelsbach-Graff Diamond will be on display for first time in 50 years at the National Museum of Natural History. (Courtesy of Wittelsbach-Graff)
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By Jacqueline Trescott
Washington Post Staff Writer
Friday, January 29, 2010

After decades of speculation, the truth can now be told: The famed Hope Diamond and its chief rival, the Wittelsbach-Graff Diamond, were not cut from the same stone, according to a group of scientists led by Jeffrey Post, curator of the National Gem Collection at the Smithsonian Institution, which tested the two storied blue diamonds extensively.

"There is an uncanny resemblance, but they are different," said Post, who announced his team's findings on Thursday at the Smithsonian's National Museum of Natural History. "They are not part of the same crystal or rough. Perhaps they are distant cousins, but not brothers and sisters."

The pair of diamonds were examined under a variety of microscopes and lights at the Smithsonian last week to try to settle some centuries-old mysteries. Could the two have originally been part of the same diamond? Are they twins? Why do they look so similar to the naked eye?

The opportunity to probe deeply into these questions came about because the Wittelsbach-Graff Diamond has been lent to the Smithsonian for a bit more than six months. Starting Friday, the slightly smaller diamond will be displayed in the same hall as the Hope.

A hidden gem

Both scientists and the general public have been anticipating the rare pairing of these two famous stones, because Wittelsbach-Graff has not been on public display for more than 50 years.

"This is the most famous diamond people have never seen," said Post, a tall, outgoing man with an encyclopedic knowledge of minerals and gems. Earlier this week, he gave a reporter a peek at the Wittelsbach-Graff. "Literally, generations have gone by when no one has seen it," Post said of the diamond, which was last shown to the public in 1958.

But now researchers have peered closely into the gem's many facets.

"The tests supported the fact that they are extremely similar, in their color, in the way they phosphoresce. It's amazingly similar," Post said. At the same time, the differences became quickly apparent under a diamond view microscope that showed dislocations, and a light microscope that showed the cross polarizers.

"The detailed pattern is different in the two. The cross polarizer reveals evidence of strain. Under the light you see the pattern and it was very different in the Hope than the Wittelsbach," Post said. "We can't match them up as the same diamond. It is likely that they had a very similar geologic history, but did not come from the same original stone."

Sparkling lineages

Like the Hope, the slightly smaller Wittelsbach-Graff blue diamond has an interesting history connected to famous names of the past.

The Wittelsbach-Graff is 31.06 carats and, like the Hope, boasts a penetrating, though slightly less intense, blue color. (It is two-thirds the size of the Hope, and two-thirds as blue.) The diamond entered into jewelry lore in the 17th century, when it was given by Philip IV of Spain to his daughter, the Infanta Margarita Teresa, upon her engagement to Emperor Leopold I of Austria. The diamond ended up with the House of Wittelsbach, a ruling Bavarian family, in 1722.


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