Blue Moon of Josephine

{{short description|Blue diamond, sold for record 48.4 million in November 2015}}

{{Infobox diamond

| image = 170px

| caption =

| name = Blue Moon of Josephine

| carats = 12.03

| color = Fancy Vivid Blue

| cut = Cushion-Shaped

| cutter =

| owner = Joseph Lau

| value = US $48.4 million

}}

The Blue Moon of Josephine is a {{convert|12.03|carat|g}} 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).{{cite news |title=Billionaire buys Blue Moon diamond for 9 year daughter for record $68m |url=http://www.abc.net.au/news/2015-11-12/blue-moon-diamond-sells-for-record-68-million/6935194 |access-date=12 November 2015 |work=ABC News |publisher=Australian Broadcasting Corporation |date=12 November 2015}} The diamond is the largest cushion-shaped blue stone classified as "fancy vivid" ever to appear at auction.{{cite news|url=https://www.theguardian.com/world/2015/nov/12/billionaire-buys-9-year-old-daughter-blue-moon-diamond-for-record-48m|title=Billionaire buys 7-year-old daughter Blue Moon diamond for record $48m|date=12 November 2015|work=The Guardian|access-date=12 November 2015}}

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.

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 {{convert|16.08|carat|g}} 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.{{cite news |url=https://www.theguardian.com/world/2015/nov/11/the-sweet-josephine-rare-pink-diamond-sold-in-geneva-auction|title=The Sweet Josephine: rare pink diamond sold in Geneva auction|date=12 November 2015 |work=The Guardian|access-date=12 November 2015}} In 2009, Lau bought another blue diamond for $9.5 million that he renamed the "Star of Josephine". The seller was Ehud Arye Laniado, a diamond trader.{{cite news |last1=Daniel Sugarman |title=Belgian-Israeli billionaire Ehud Arye Laniado dies during penis enlargement surgery |url=https://www.thejc.com/news/world/belgian-israeli-billionaire-ehud-arye-laniado-dies-during-penis-enlargement-surgery-1.481188 |access-date=10 March 2019 |work=The JC |date=8 March 2018 |quote=In 2015, he sold the world’s most expensive diamond, the Blue Moon of Josephine, to a Hong Kong billionaire and convicted felon, Joseph Lau Luen Hung}}

The diamond exhibits red phosphorescence when observed under ultraviolet light.