Modern Mining August 2015

RUBIES

Gemfields’ Montepuez ruby mine

Montepuez is said to be the world’s largest ruby and conundrum deposit. Gemfields acquired its 75 %-stake in 2011 from Mwiriti Lda for a total consideration of US$2,5 million and the acquisition was completed in February 2012. Montepuez Ruby Mining Lda (MRM) is the project operator and represents a joint venture between Gemfields and Mwiriti. Although still in the bulk sampling phase, Montepuez is already a fairly substantial operation, with 369 employees (including 51 expatriates), 248 contract security personnel, as well as additional civil and drilling contract employees. There is a semi-mobile 100 t/h wash plant, complete with jigs, on site plus a sorting house while the Gemfields-operated mining fleet consists of six excavators, 17 ADTs and 18 tipper trucks. A 10 km long powerline connects the site to Mozambique’s national grid but backup generators are also available. Water (potable and process) is sourced from seven boreholes. Gemstones are currently mined from a series of shallow open pits. Some 45 % of the total production is being sourced from the Maninge Nice pit, a primary amphibolite deposit that extends up to 28 m below surface, with the balance coming from the Mugloto pits, which extract secondary gravel deposits originating from ancient river channels. Most of the mate- rial is free dig with some of the harder laterite needing to be ripped by a bulldozer. Bulk sampling operations started in August 2012 and have continued to scale up progres- sively, producing consistently encouraging results, says Gemfields. As of July this year,

“This, together with various expansion opportunities that are already at hand, and the impact that our continued global market- ing and promotional initiatives are expected to generate, deliver a high level of confidence in Gemfields’ ongoing efforts to reinvigorate the global coloured gemstone market place. As I have said on many occasions over the past few years, this is still just the very beginning, with much more yet to come. I would also like to thank Mwiriti and the Mozambican govern- ment for their continued support.” Discovered in 2009 and located in the north-east of Mozambique in Cabo Delgado Province approximately 170 km west of Pemba,

Gemstones are currently mined from a series of shallow open pits. There are two main operating areas – Mugloto and Maninge Nice.

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