GIA gets inside look at African emerald mine

During the GIA’s most recent research trip to emerald mines in Zambia, Robert Gessner from Gemfields explained the local geology at the Kagem mine to Tao Hsu, Andrew Lucas and Stanislas Detroyat. Photo credit: Vincent Pardieu, GIACarlsbad, Calif.--Last month, field researchers with the Gemological Institute of America took a trip to Zambia to collect emerald samples for the organization’s gem identification database and to document the current state of the Kagem mine.

The team--which included field gemologists Vincent Pardieu and Andrew Lucas, Gems & Gemology Technical Editor Tao Hsu, videographer Didier Gruel and expedition guest Stanislas Detroyat--visited the site to see firsthand what’s behind the success of the world’s largest emerald mining operation.

Gemfields acquired the open-pit mine six years ago, and since has increased mining from 3,000 to 8,000 tons per month, and rock handling from 125,000 to 750,000 tons per month.

According to the GIA, the colored gemstone miner has combined an understanding of geology with professional mining methods to turn Kagem into a profitable operation. The company’s first high-quality rough emerald auction in July 2009 achieved $5.9 million, while in February 2014 an auction of the same material hit $36 million.

“I’ve visited numerous colored gemstone mining operations throughout the world, but one of this size, modernization and organization really gives a visual of the changes that may be coming to our industry,” Lucas said.

In addition to the standardized grading systems for rough emeralds and an auction platform that it has developed, Gemfields has innovated the mine-to-market process at Kagem with environmentally friendly practices and community outreach programs.

The company uses in-pit dumping to ensure that environmental impact is kept low, while technical output of the mine has been increased through methods like exploratory drilling, mapping of pegmatite and talc magnetite schist, resource calculations and mining software.

The GIA team also visited other emerald mines in Zambia to collect comparative samples including Musakashi in the Solwesi province, and operations in the Kafubu area like Miku, Dabuisha, Matenke and Benisa.

“It was fascinating to visit and study the Kafubu emerald mining area, one of the oldest gemstone producing areas in Africa, and to witness the challenges faced by the local miners,” Pardieu said. “In comparison to other gems, emerald is very difficult to mine since it’s mainly mined from primary deposits and production is technically much more challenging.”

The GIA regularly conducts research