South Africa-focused miner Rockwell Diamonds lifted first-quarter revenues from its own operations by 31% to $6.57-million, boosted by high-grade diamonds from its Middle Orange River region operations.

The Vancouver-based company improved revenues despite placing its Tirisano mine on care and maintenance late in 2012 and selling its Klipdam mine early in the quarter ended May 31.

Total sales from the company’s own operations totalled 3 257 ct at an average price of $2 018/ct. The total carats sold from its own operations declined by 38% from 5 229 ct to 3 257 ct, as the company transitioned its production focus exclusively to operations in the Middle Orange River region, which typically yields gem-quality diamonds.

Rockwell’s Saxendrift mine achieved a 48% year-on-year increase in the average price per carat received, selling each carat for about $2 553, resulting in the value of sales rising by 56% year-on-year during the period.

The first 130 ct of diamonds sold from the newly commissioned Saxendrift Hill complex were also recorded at an average price of $3 668/ct. Royalties payable to Rockwell on diamond sales from the three royalty mining contracts at Tirisano totalled $134 749 in the first quarter.

The company's 12.5% royalty from these sales was applied against the care-and-maintenance costs at Tirisano. Rockwell said it planned to conclude two new contracts at Tirisano and another agreement for Zwemkuil, which is also located in the Middle Orange River region.

Meanwhile, the sale of several large, high-valued diamonds recovered in this region contributed to a 109% increase in the average price per carat from a year earlier. Rockwell produced several large stones at all operations, including the recovery of 44 stones exceeding 10 ct each.

These diamonds were channelled into the company's beneficiation joint venture with Steinmetz Diamonds (SD), which would deliver value-added future revenues to Rockwell for stones larger than 2.8 ct that were polished and sold by SD.

Rockwell last week reported a 33% decline in its first-quarter diamond output, reflecting a company in transition, as it focused on growing a production profile that would deliver better efficiencies and greater economies of scale.

The company said diamond output for the quarter totalled 4 824 ct, significantly less than the 7 234 ct produced in the same period of the previous financial year.