According to real estate brokers Compass, in 2021 most U.S. markets saw strong sales for what they term ultra-luxury homes—those with a price above $10 million. Los Angeles saw more of these highest of high-end properties change hands than anywhere else

The largest white diamond to ever be sold publicly could fetch as much as $30 million when it goes to auction in Switzerland in May, as prices and demand for diamonds continue to rebound after an initial pandemic slump.

Dubbed “The Rock,” the jewel is a 228.31-carat pear-shaped diamond that was mined and polished in South Africa 20 years ago, according to Christie’s, which said it was among the finest gemstones to pass through the auction house since its founding in 1766.

The gem will break the record for the largest auctioned diamond set in 2017, when a 163.41-carat white diamond sold for $33.7 million, also through Christie’s Geneva.

The Gemmological Institute of America graded the gem as a G color, VS1 clarity diamond, and the sale will include a letter from the laboratory stating “The Rock” is the largest pear-shaped diamond to be graded by the institute, according to Christie’s.

The stone will go on a worldwide tour before the May auction, stopping first at Christie’s showrooms in Dubai, Taipei and New York, and then sent to Geneva, where it will be one of the jewels of Christie’s Luxury Week auctions.

Christie’s first brokered the private sale of the gem to a collector nearly two decades ago, and the seller recently approached the auction house to sell back “The Rock” on the public market after the demand for diamonds increased last year, Christie’s international head of jewelry ​​Rahul Kadakia told Bloomberg.