Petra Diamonds finds its second largest diamond at mine which produced crown jewel stones

The stone could fetch up to $35m at aution, analysts said

Petra Diamonds found the second largest diamond in its history last week in the South African mine where the world’s biggest stone was found over a century ago.


The 425.1 carat diamond is a type II - the most collectable form which only makes up a fraction of global stocks. It is also completely colourless.

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Analysts at the Royal Bank of Canada said the stone is likely to fetch between $25m and $35m ten years after Petra sold a similar 507 carat stone for a then-record $35m.

The miner also found a 101 carat diamond on 8 March this year.


“These stones reaffirm management’s message on: the prevalence of these higher value stone types at Cullinan; and that the mine’s plant is successfully recovering them,” said RBC analyst Tyler Broda.

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“Any higher value stones will undoubtedly help to offset ongoing challenging price trends in lower value stones as was recently highlighted by a recent weak second sight from De Beers.”

The stone was found at the Cullinan mine, where explorers discovered the Cullinan diamond, a 3,106 carat beast in 1905. Two of the stones cut from the Cullinan were used to decorate the crown jewels.