The announcement comes as the group reported its YTD sales reached $405.3m (£308.12m), while full year sales in FY21 were $406.9m (£309.34m), with further tenders for FY22 due to be held in April and June.
Overall, like-for-like rough diamond prices increased by 46.5% in the six months to December 2021 and 37.6% on Tender 3 which closed around 15 December 2021.
Petra Diamonds said it experienced “strong” demand with resultant price increases across all size and quality categories.
Demand reportedly spanned the entire spectrum of rough assortments and sizes, with a “notable” increase in the price of larger stones, particularly the white D-colours and “fancy” coloured diamonds.
This tender included one “exceptional stone”, a rough diamond that sells for $5m (£380.12m) or more each, from the Cullinan mine which was a 157.8ct white stone sold for $5.5m (£418.13m).
Richard Duffy, chief executive of Petra, said: “The tender of the group’s South African operations was hosted in South Africa for the first time since the Covid-19 pandemic took hold and was extremely well attended.
“These strong sales results support the robust health across the diamond value chain that has been evident since mid-2021. Current pricing in the rough market is being driven by strong sales of polished and increased demand from the manufacturing centres, bolstered by record sales during the festive season that have continued into the new year.”
He added: “Whilst we believe this market reflects the structural change in underlying supply and demand dynamics, which we expect to continue in the medium term, it is too soon to determine what impact the current conflict in Ukraine will have on the global economy and the diamond market specifically.”