Australian junior miner Lucapa Diamond Co. held the first sale of diamonds at the Bonas tender house in Antwerp from the new 1.1Mtpa Mothae kimberlite plant in Lesotho, marking the mine's arrival on the international market. The parcel of 5,411 carats of rough diamonds recovered during the plant ramp-up phase in Q4 2018 and in the first month of commercial mining operations at Mothae in January 2019 sold at tender in Antwerp for a total of US$3.8 million. The sale achieved an overall average price per carat of US$707 (A$987) for the total run of mine parcel, with the highest price achieved for an individual Mothae diamond reaching US$36,664 per carat.
Lucapa Managing Director Stephen Wetherall said Lucapa and the Government of Lesotho were extremely pleased with the results of the first sale of Mothae diamonds. “The solid bidding we witnessed in Antwerp for this first commercial parcel has certainly marked Mothae’s arrival on the international scene as a producer of top-quality goods, complementing those from our Lulo mine,” said Mr Wetherall. “The strong sales prices achieved for our quality run of mine production, in the absence of a single stand-out stone, represent a great start for Mothae which augurs well for its future as a producer of exceptional diamonds and its contribution to the Basotho nation.” A delegation of ministers and miners from Lesotho, including the Minister of Mining Mr Keketso Sello visited the Antwerp World Diamond Centre (AWDC) and its Diamond Office during the final days of the tender.
As the miner explains, the average price per carat was dragged down somewhat by the inclusion of a larger number of smaller diamonds than the mine's modeled profile. They note that the efficiency of the new Mothae plant in treating the near surface weathered material has resulted in the liberation of additional diamonds, primarily small stones below the plant’s 3mm bottom cut-off screen size (“BCOS”). "Most of these additional small diamonds are in the -11 and below sieve size fractions, and while these small diamonds generate additional revenue, they also reduce the overall average price per carat," the miner explains. Lucapa expects the recovery of small diamonds below the 3mm BCOS through the Mothae plant to normalise or diminish as mining progresses into the more competent kimberlite material with depth.
The ~4,100 carats of Mothae diamonds included in the sale parcel in the +11 sieve size fraction and above sold for about US$3.78 million, representing an average price per carat of ~US$900 (~A$1,260). In contrast, the ~1,300 carats of small Mothae diamonds in the -11 sieve size fraction and below sold for ~ US$46,000, representing an average price per carat of just US$36. Lucapa plans to update guidance for the Mothae mine in respect of volume, grade and price in Q2 2019 after the first quarter of commercial mining operations.