Sotheby’s auction world record April 2018 rare fancy intense blue diamond ring

The cut-cornered, rectangular, step-cut 3.47-carat stone rare fancy intense blue diamond ring (pictured Courtesy Sotheby’s) set a price-per-carat world record for a blue diamond, selling for $1.9 million per carat at the Magnificent Jewels Auction, Sotheby’s said Friday. The $6.663,300 million final price nearly tripled Sotheby’s pre-sale estimate of between $2 million and $2.5 million