Wittlesbach-Graff Diamond Unveiled at AMNH

The Wittlesbach-Graff Diamond was finally unveiled at the American Museum of Natural History. In a category known as Type IIb, this type of diamond is believed to make up less than half of one percent of all diamonds found in nature, putting the Wittlesbach-Graff alongside very rare company such as the 70.21-carat Idol’s Eye and the 45.52-carat Hope Diamond. These types of stones get their distinctive blue hue from the absence of nitrogen and presence of boron. They are also semiconductors, which is another unusual trait.