November 2015
The Blue Moon of Josephine — A $48.4 Million Gift from Father to Daughter
The Blue Moon of Josephine, a 12.03-carat fancy vivid blue, internally flawless, cushion-shaped diamond, sold at Sotheby's Geneva on 11 November 2015 for US$48.4 million — approximately US$4.03 million per carat, a per-carat record for any diamond at the time. The buyer was Hong Kong property tycoon Joseph Lau Luen-hung, who named the stone after his then-seven-year-old daughter, Josephine.
The Blue Moon was discovered as rough in South Africa's Cullinan mine in January 2014, weighing 29.6 carats. It took six months of careful planning and cutting to produce the 12.03-carat polished stone — a yield of roughly 40%, which is typical for fancy color diamonds where the priority is maximizing color saturation rather than retaining weight. Joseph Lau, one of Hong Kong's most prolific collectors of rare gems, has a habit of naming his purchases after his daughters: the previous day, he had bought a 16.08-carat pink diamond at Christie's for US$28.5 million and named it the Sweet Josephine. Together, the two purchases cost him roughly US$77 million in 48 hours — a spending spree that, even by the standards of billionaires, raised eyebrows. The Blue Moon's per-carat record stood until May 2016, when the Oppenheimer Blue narrowly eclipsed it.