Coloured gemstone miner Gemfields reported a 7% rise in revenue to US$ 171.4 mn for the year ended June 30, 2015 (2014: US$ 160.1 mn), but said that profits after tax during the period at US$ 12.3 mn were 24% lower than the previous year (US$ 16.3 mn).

The company described the year as one of “growth and performance”, and said that it had “achieved record revenues and met or exceeded production guidance” at its Kagem emerald and Montepuez ruby mines.

At Kagem (where Gemfields has a 75% stake), annual production of emerald and beryl stood at 30.1 million carats (2014: 20.2 million carats). The average grade was 242 carats per tonne, inclusive of ore from bulk sampling pits (2014: 253 carats per tonne) and unit operating costs decreased from US$1.58 per carat to US$1.48 per carat.

At the 75% owned Montepuez Ruby Mining Limitada, annual production of ruby and corundum rose to 8.4 million carats (2014: 6.5 million carats), with the increase in processed volumes being primarily due to continued upgrades to the wash plant design. The reported grade was 26 carats per tonne (2014: 41 carats per tonne), while unit operating costs rose from US$1.12 per carat to US$2.57 per carat due to a greater proportion of lower grade but significantly higher quality alluvial deposit ore being processed during the year.

Ian Harebottle, CEO of Gemfields, commented: “Demand for coloured gemstones remained strong throughout the year, as is clearly demonstrated by the results of the six auctions held during the period which saw various record per carat prices being achieved. This is a reflection of our continued marketing campaigns, the market's recognition of the quality of our coloured gemstones and the consistent way in which we are able to support the downstream sector’s business needs.”

In the current fiscal year, Gemfields has already released the findings of two independent studies confirming a 25 year life of mine and increasing production to 40-45 million carats per annumat Kagem and a 21 year mine life producing 20 million carats per annum at Montepuez.

The company also entered into binding agreements to acquire controlling interests in two emerald projects with operations and prospects in Colombia.