Petra Puts 39-Carat Blue Diamond Up for Sale
Miner Petra Diamonds recovered this 39.34-carat Type IIb blue diamond from the Cullinan Mine
By Michelle Graff June 21, 2021
London—Petra Diamonds Ltd. has released details on the sale process for the nearly-40-carat blue diamond it recovered from the Cullinan mine in April, a remarkable stone expected to sell for upward of $50 million.
In an interview with National Jeweler last week, George Togholian, a gemologist at L.J. West Diamonds, compared the 39.34-carat diamond to another big chunk of blue rough mined at Cullinan in January 2014—the 29-carat stone that became the $48.5 million “Blue Moon of Josephine.”
“This is a special tone of blue. It’s not comparable to any other diamond that comes to auction,” Togholian said.
“In my opinion, these are the best of the blues. This is on another level.”
While he declined to share his guess as to the diamond’s sale price, Togholian did note the 39-carat rough probably will deliver about a 40 percent yield—the yield for blues and pinks is generally less than yellow or white diamonds because the material is not as smooth, he noted—which means a polished diamond of about 15 to 16 carats.