Gemfields (LON:GEM) will focus on improving gemstone production volumes in coming months, the company said, as it unveiled "pleasing" half year results.
Efficiency measures continue at its Kagem mine in Zambia, targeting
higher grade areas and reducing operating costs, it said.
There is increasing demand for the firm's products, which is likely to continue for the near to medium term.
Meanwhile, the completed purchase of a controlling stake in a ruby deposit in Mozambique offers exciting prospects for the firm to broaden its global footprint, it told investors.
For the six months to December 31 last year, Gemfields said revenue from rough and finished emerald sales was up by 57 per cent to US$45.7 million compared to US$29.1 million in 2010.
EBITDA (earnings before interest, tax, depreciation and amortisation)was up by 107 per cent to US$32.2 million.
As at year-end, the firm had cash of US$32.4 million, compared to US$15.5 million a year earlier.
"Gemfields has once again delivered pleasing results in the first half of this new financial year," said chairman Graham Mascall in the statement.
"The results justify our expectations for the continued growth and success of the company and the coloured gemstone sector as a whole.
"The sector has been undercapitalised and undervalued for some time and Gemfields believes it is now poised for a period of dynamic growth."
CEO Ian Harebottle added: "Gemfields has once again enjoyed a financially robust first half with increasing demand, solid financial controls and improving operating efficiencies underpinning gratifying margins."
Since the beginning of 2012, key developments for the firm have included the acquisition of a 75 per cent stake in the ruby deposit in the Montepuez district of the Cabo Delgado province in Mozambique.
In addition, diamond drilling and bulk sampling have been carried out in key targets within the Kagem licence area.
Two auctions of rough emerald and beryl are scheduled prior to the end of the financial year, added the company, while the next emerald auction will be held in Singapore from March 19 - 24 this year.