The Oppenheimer Blue sold on Wednesday for more than $57.5 million including fees at a Christie's auction in Geneva, making it the most expensive diamond ever sold.

It is now on display at the Smithsonian National ... Gems made this way are significantly less expensive than naturally black diamonds. Celebrities wearing black diamond jewelry are fueling ...

and the more expensive ones are typically — but not always — transferred to the National Archives or put on official displays. The $20,000 diamond was retained for official use in the White ...

Only 4% of brown diamonds ... display of colors, compared to common opal, which is usually one color. High-quality black opal can cost over $10,000 per carat, making it one of the world's most ...

A rare Russian pink diamond called the ‘ Spirit of the Rose ’ has set the new world record for the most expensive purple-pink diamond ever sold. The 14.83 carat diamond was auctioned for a ...