Billionaire Buys 7-Year-Old Daughter Most Expensive Diamond Ever

Hong Kong billionaire Joseph Lau shelled out a record $48.5 million to buy the “Blue Moon” diamond at a Sotheby’s auction Wednesday, renaming the 12.03-carat diamond the “Blue Moon of Josephine” in honor of his daughter.

The sale makes the diamond the most expensive jewel ever sold at auction, according to Sotheby’s BID 3.94% . It also netted the highest-ever price per carat—over $4 million.

The previous record for the most expensive jewel bought at auction was for a 24.78-carat pink diamond dubbed the “Graff Pink.” It sold for $45.6 million in 2010 to Laurence Graff, a London jewelry dealer.

Lau, a 64-year-old property tycoon, also paid $28.5 million for a 16.08-carat pink diamond earlier this week that he renamed the “Sweet Josephine,” also after his daughter, reported the Guardian. That adds to a growing collection for young Josephine. Lau bought a blue diamond in 2009 for $9.5 million, naming it the “Star of Josephine.”

This article originally appeared on Fortune.com.