The Blue Moon of Josephine

The Blue Moon of Josephine is a 12.03 carat (2.406 g) blue diamond that was discovered in South Africa in January 2014 and sold for a record-breaking price of $48.4 million at a Sotheby's auction in Geneva in November 2015. The cushion-shaped bluestone, one of the most expensive pieces of jewelry, is the largest "fancy vivid" cushion-shaped blue gem ever sold at auction.

According to David Bennett, the head of Sotheby's international jewelry division, the "Blue Moon" sale set a record for the highest-ever price per carat, making the diamond the most expensive jewel ever sold at auction as well world's most expensive diamond, regardless of color.

The diamond was purchased by Hong Kong businessman and fugitive convicted felon Joseph Lau Luen-hung, who called it Josephine after his seven-year-old daughter. The day before the "Blue Moon" auction, Lau paid $28.5 million for a 16.08 carat (3.216 g) pink diamond at a Christie's auction, a record price for a jewel of its kind, and nicknamed it the "Sweet Josephine" diamond. Lau paid $9.5 million for another blue diamond in 2009, which he called the "Star of Josephine".

Price: $48.4 million