| Blue Moon of Josephine | |
| Carats: | 12.03 |
| Color: | Fancy Vivid Blue |
| Cut: | Cushion-Shaped |
| Owner: | Joseph Lau |
| Value: | US $48.4 million |
The Blue Moon of Josephine is a 12.03carat blue diamond, described as flawless by experts, that was discovered in South Africa in January 2014 and was sold at a Sotheby's auction in Geneva in November 2015 at a record-setting price of $48.4 million (43.2 million Swiss francs plus fees).[1] The diamond is the largest cushion-shaped blue stone classified as "fancy vivid" ever to appear at auction.[2]
The "Blue Moon" sale, according to David Bennett, the head of Sotheby's international jewellery division, set a record for the highest-ever price per carat and it made the diamond both the most expensive jewel ever sold at auction and the world's most expensive diamond, regardless of color.[1] [2]
The diamond was bought by the Hong Kong billionaire, and fugitive convicted felon, Joseph Lau Luen-hung, who named it for his seven-year-old daughter, Josephine. On the day before the "Blue Moon" sale, Lau had purchased a 16.08carat pink diamond at a Christie's auction for $28.5 million, a record price for a jewel of its kind, and renamed it the "Sweet Josephine" diamond.[3] In 2009, Lau bought another blue diamond for $9.5 million that he renamed the "Star of Josephine".[2] The seller was Ehud Arye Laniado, a diamond trader.[4]
The diamond exhibits red phosphorescence when observed under ultraviolet light.[5]