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March 4 (Reuters) - Emerald miner Gemfields Plc saidfirst-half core earnings fell 39 percent as it held just oneauction during the period compared with two in the prior year,but production climbed by two-thirds.
Demand for precious stones and jewellery has been volatile,hit by the euro zone crisis and a slowdown in growth in keymarkets like India and China.
Gemfields said gemstone production rose about 65 percent to14.5 million carats in the first half, mainly on higher gradesrecovered at its Kagem mine in Zambia.
"Significant interest from downstream stakeholders inattending the Gemfields' auctions provides sound evidence ofongoing healthy demand," the company said.
Gemfields is scheduled to have two auctions for its secondhalf ending June 30.
The company, which named actress Mila Kunis its brandambassador earlier this month, mainly mines emeralds at theKagem mine, but also has interests in ruby and sapphiredeposits.
Earnings before interest, tax, depreciation and amortisationfell to $19.5 million for the six months to Dec.31, from $32.2million a year earlier.
Revenue from rough and finished emerald sales decreased 39percent to $27.7 million.
In November, Gemfields agreed to buy luxury jewellerFaberge, the maker of lavish Easter eggs for Russia's last tsar,in a deal valued at $142 million.
The miner's shares, which have fallen about 12 percent sincethe company announced the Faberge deal, closed at 30.875 penceon the London Stock Exchange on Friday.
