GIA researchers explore ruby deposit in Mozambique

A team of GIA (Gemological Institute of America) field researchers visited the Montepuez mining area of Mozambique, in early September 2014, to collect ruby samples for the Institute’s gem identification database and to document the current state of the deposit. The GIA team, consisting of Field Gemologists Andrew Lucas and Vincent Pardieu, Gems & Gemology (G&G) Technical Editor Tao Hsu, videographer Didier Gruel and expedition guest Stanislas Detroyat, discovered an ample variety of ruby specimens ranging in size, color and iron content.

This is the third expedition of GIA researchers to the Montepuez ruby deposit since its discovery in 2009. The Montepuez Ruby Mining Company (MRM) has rapidly expanded since operations reached the production stage in 2012, handling 1.6 million tons of rock and recovering eight million carats of ruby and corundum to date.

“It is truly fascinating to witness the evolution of this major deposit. While it is clear from our expedition that the MRM operation has reached production stage, I believe that this is just the beginning. The deposit seems to be incredibly rich, easy to mine and conveniently located along a major road and close to Mozambique’s port city of Pemba,” said Pardieu.

At the MRM, two types of deposits are found: at Maninge Nice, rubies in a primary deposit associated with amphibole, mica and feldspar. In Mugloto, Ntorro and Glass, rubies are found in secondary deposits along current or former river beds. The company is currently focusing mining production on secondary deposits in the Mugloto area since it is shallow (4-8 meters) and rich in high quality clean rubies, a result of millions of years of weathering. Although the mine is in production, exploration continues at a fast pace, with core drilling into primary deposits and auger drilling into secondary deposits. “This deposit will not only change the supply structure of ruby on the global market, but may also contribute to changing the way business is done in the ruby trade,” added Lucas.