(IDEX Online News) – Emerald, beryl, ruby and corundum miner, Gemfields plc, has reported its fourth quarter results for the 2016 fiscal year, ended June 30, which showed fluctuating production outputs.

Production of emerald and beryl from the company’s 75-percent owned Kagem Mining Limited in Zambia, showed a decline, falling to 7.2 million carats compared to 8.1 million carats over the same period in the prior year. Average grade also declined to 185 carats per ton compared to 222 carats per ton in the same period in 2015.

Annual gemstone production of emerald and beryl of 30 million carats from the mine was in line with company guidance and showed only a 100,000 carat decline compared to the year ended June 2015. Average grade slipped to 241 carats per ton compared to 242 carats per ton over the same period in the prior year.

An auction of predominantly commercial quality rough emerald in Jaipur, India, from May 17-20, generated revenues of $14.3 million at an average value of $5.15 per carat. Gemfields held four rough emerald and beryl auctions during the year, delivering auction revenues of $101.3 million at an overall average value of $12.22 per carat.

The company’s production of ruby and corundum at its 75-percent owned Montepuez Ruby Mining Limited in Mozambique, rose to 6.2 million carats compared to only 0.7 million carats in the quarter ending June 30, 2015. Average grade showed a dramatic increase, improving to 75 carats per ton compared to 9 carats per ton over the same period in the prior year, due to a greater proportion of higher grade ore being processed.

Annual gemstone production of ruby and corundum reached 10.3 million carats compared to 8.4 million carats for the year ending June 30, 2015, and beyond the company’s 8 million carats guidance. Average grade was 35 carats per ton compared to 26 carats per ton over the same period in the prior year.

An auction of mixed quality rough rubies was held in Singapore from June 13-19, and which generated revenues of $44.3 million at an average value of $29.21 per carat. During the financial year 2015-2016 Gemfields had two rough ruby and corundum auctions, which realized $73.1 million in revenues at an overall average value of $45.50 per carat.

Gemfields’ next auction of Kagem emerald and beryl is scheduled to take place in Jaipur in September, followed by an auction of Montepeuz rough ruby expected to take place in Singapore in December.