Petra Diamonds Limited (LON:PDL) has found a 425.1-carat diamond at its renowned Cullinan diamond mine in South Africa, which analysts think could be worth as much as US$35mln.
Shares in the miner surged 9.3% to 19.8p on the back of the discovery.
READ: Petra recovers 100-carat stone from Cullinan
The diamond is the second-largest ever recovered at Cullinan by Petra, behind only the 507-carat stone found almost a decade ago.
When that gem went under the hammer in 2009, it fetched a then-record US$35mln.
Analysts at RBC Capital said while it is tough to determine a value for this latest diamond right now, somewhere between US$25-35mln “may be reasonable”, given what was paid for the larger gemstone.
The new find, one of a string of recent high-profile discoveries at Cullinan, is a type II, D-colour diamond.
D is the highest colour grade and type II diamonds have no impurities, making stones that tick both boxes extremely rare and therefore expensive.
‘Important step in right direction’
“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 DeBeers,” said RBC in a note to clients.
“Given an H1 FY19 price of US$96/ct at Cullinan, large stones will be important to meeting FY19 pricing expectations at the mine.
“To us today marks another important step in the right direction and should provide a boost for financial and operational perceptions around the company.”