(IDEX Online News) – A rise in output at the Argyle diamond mine in Australia helped Rio Tinto to a 38-percent jump in production on the year in the fourth quarter.
The diversified miner reported production in the quarter of 4.489 million carats.
For all of 2013, Rio's diamond production jumped 22 percent on 2012 to 16.027 million carats.
Output at its 100-percent owned Argyle mine surged 57 percent to 3.153 million carats, which the firm attributed to a rise in processed ore and higher-grade ore after it began underground operations at the mine in April 2013. Production for last year at the mine soared 35 percent to 11.395 million carats.
Meanwhile, there was a 9-percent rise in output to 1.240 million carats from its 60-percent holding in the Diavik mine in Canada's NorthWest Territories as a result of a rise in ore processed as the underground mine increased its production capacity. However, this was offset by lower grades.
The miner's share of production at Diavik inched up 0.2 percent to 4.346 million carats for 2013 as a whole.
Rio Tinto reported a 7-percent increase in output at its Murowa mine in Zimbabwe to 105,000 carats. The firm owns 78 percent of the operation. For all of 2013, production edged up 3 percent to 322,000 carats.