PETRA'S Williamson Diamond production has registered a 17-per cent increase this year being a four-decade high output.
The mine output, according to Petra Diamond report, rose to 399,615 carats in year ending June from 341,102 carats similar period last year.
"The mine performed well with production up 17 per cent, the highest level of production achieved by the mine in over 40 years," the report issued on Tuesday shows.
The firm said the best performance was despite operations being impacted by cash constraints.
"[The constraints is] due to the parcel of 71,654 carats that remains blocked for export and the overdue VAT receivables... ," the largest diamond mine based in Mwadui, Shinyanga said.
The VAT overdue stands at 32.9 million US dollars for a year ending June up from 24.2 million US dollars of similar period last year.
Nevertheless, the diamond mine revenue increased by 36 per cent to 93 million US dollars from 68.5 million US dollars. The revenue increase was attributed to rise in "production and resultant higher sales volumes, offset by lower prices per carat achieved."
The positive impact on the unit cost of increased volumes treated was offset by the normalisation of costs, following the severe cost cutting measures implemented in last year required due to the mine's liquidity constraints.
The total on-mine cash cost for next year is guided at ca. 62 million US dollars while capital expenditure for this year was 8.6 million US dollars mainly related to in-pit waste stripping activities.
The mine despite having been in operation since 1940, the pit is only 95 metres at its deepest point due to the large size of the deposit.