Chicken-Egg-Sized Gem May Fetch $31 Million

Published on 01/12/09

Petra Diamonds Ltd., a miner of the stones in Africa, may get $31 million for the chicken-egg-sized diamond it unearthed in September, BMO Capital Markets said.

Petra, which said last week that it sold a 168-carat gem found at its Cullinan mine in South Africa for $6.28 million, or $37.380 a carat, may get 50 percent more per carat for the larger stone, BMO analyst Edward Sterck wrote in a research note dated Nov. 27.

The 507.6-carat stone, the size of a medium chicken egg and weighing more than 100 grams (3.53 ounces), may be among the 20 largest “high quality” rough diamonds discovered, St. Helier, Jersey-based Petra said in September. The company sold two other white diamonds discovered at its Cullinan mine for $2.8 million this month.

It’s too early to say how much the diamond is worth and Petra has still to decide how it will sell the diamond, spokesman Bobby Morse said by phone from London today.