In late September, GIA field gemmologist Vincent Pardieu, videographer Didier Gruel and expedition guest Stanislas Detroyat travelled to Malawi to collect samples for GIA research activities, and to document and share their findings from the deposit.

The ruby and sapphire deposit was discovered about 145 kilometers south of Malawi’s capital of Lilongwe on Chimwadzulu Hill in 1958. Though it is amongst the oldest known gemstone deposits on the African continent, very little has been published about its production in recent years.

“We discovered that this deposit shares a very similar metasomatic type geological environment with the Montepuez ruby deposit located in nearby Mozambique, as well as Winza, Tanzania and Didy, Madagascar,” said Pardieu. The team learned that rubies from the Chimwadzulu deposit are associated with amphibole, mica and feldspar. The researchers also noted that while the Chimwadzulu deposit is known for its rubies and orange sapphires, it produces mostly pale green, blue and yellow sapphires.

Going into the background, the report says that in 2008, Nyala Mines Ltd. began to work the deposit, while Colombia Gem House Inc. took charge of cutting, marketing and selling of the stones. In 2013, Malawian national Abdul Mahomed acquired 80% of the mining operation.

According to Mahomed, the report adds, the acquisition process is expected to be completed soon and the Malawi government and a local consortium will hold the remaining 20%. Since then, the mining operation has been renovated and the areas originally worked in 1958 have been further explored. Production is expected to begin in 2015. In an effort to support the local community, Columbia Gem House has set up the Dzonze District Development Fund and is supporting two villages near the mine through a school at Kandoma and a hospital in Katsekera.

 Photo cap: Abdul Mahomed, majority owner of the Chimwadzulu mine, with rubies in their amphibolite matrix. Photo by Vincent Pardieu; © GIA.