Lucapa Diamond Company has seen its revenue drop significantly in the fourth quarter as the miner delayed sales while it negotiated a partnership with manufacturer Safdico.
Overall, revenue for the year fell by 42% to $32.1m (£23.4m).
Sales from Lulo fell 32% year on year to $6.6m (£4.6m) for the three months ending 31 December.
The mining company did not gain any revenue from its Mothae mine in Lesotho due to it still finishing talks over a sales deal with the Graff subsidiary related to rough from that site.
All of Lucapa’s sales during the period went into its cutting and polishing partnership with Safdico, which would allow the manufacturer to purchase rough at market value.
Lulo’s production for the period grew 55% to 6,447 carats, while production at the Mothae deposit fell 33% to 6,603 carats.
For the year, Lucapa sold a total of 20,397 carats from Lulo for $28m (£20.4m), at an average of $1,371 (£1,001) per carat, and had 4,324 carats in inventory.