CollectionsMar 13, 2025
Chopard Unveils High Jewelry Collection Created From 6,225-Carat Emerald SourcingAug 27, 2025
11,685-Carat Emerald Recovered From Zambia’s Kagem Mine
Dubbed the “Imboo,” or “buffalo,” emerald, the rough gemstone is part of Gemfields’ latest emerald auction, which is taking place now.
“Even under the beam of a strong light that is necessary to illuminate a gemstone of this remarkable size, ‘Imboo’ reveals an intense, verdant green with golden warmth and a clarity that captivates the eye,” said Adrian Banks, Gemfields’ managing director of product and sales. (Photo courtesy of Gemfields)
Bangkok—Kagem, the emerald mine Gemfields operates in partnership with the Zambian government, has yielded its biggest gem-quality stone yet—a 11,685-carat gemstone dubbed the “Imboo,” or “buffalo,” emerald.
Recovered Aug. 3, the gigantic gemstone is being offered in Gemfields’ latest high-quality emerald auction, which began Monday and runs to Sept. 11.
In a statement issued Tuesday, Gemfields did not provide an estimated sale price for the rough emerald, with a company spokesperson noting the miner never provides the value of individual lots offered at auction, only the auction total.
However, Gemfields Managing Director of Product and Sales Adrian Banks speculated in the statement that the Imboo could produce several fine-quality polished emeralds of “significant size.”
“Such a rare collection could form an entire high jewelry suite from this single gemstone,” he said, which is what Chopard did with the 6,225-carat “Insofu” emerald, also recovered from Kagem.
Recovered Aug. 3, the gigantic gemstone is being offered in Gemfields’ latest high-quality emerald auction, which began Monday and runs to Sept. 11.
In a statement issued Tuesday, Gemfields did not provide an estimated sale price for the rough emerald, with a company spokesperson noting the miner never provides the value of individual lots offered at auction, only the auction total.
However, Gemfields Managing Director of Product and Sales Adrian Banks speculated in the statement that the Imboo could produce several fine-quality polished emeralds of “significant size.”
“Such a rare collection could form an entire high jewelry suite from this single gemstone,” he said, which is what Chopard did with the 6,225-carat “Insofu” emerald, also recovered from Kagem.
“In my 30 years at Kagem, I’ve rarely seen such a remarkable formation of large, high-quality crystals. This is a true masterpiece carved by nature’s hand.” — Jackson Mtonga, Kagem sort house
According to Gemfields, geologist Dharanidhar Seth and Justin Banda, a veteran miner said to be “instrumental” in the extraction of many noteworthy gems, discovered the over 11,000-carat emerald in the mine’s Chama pit.
The pit is the portion of the mine that has yielded large emeralds in the past.
The Insofu was discovered there in 2010, followed by the 5,655-carat “Inkalamu” emerald in 2018, and the 7,525-carat “Chipembele” emerald in 2021.
Gemfields said the composition of Chama is a classic example of what’s known as a triple junction, where three distinct lithological and structural domains converge.
In the case of Kagem, which is located in Zambia’s Copperbelt Province, they are a talc-magnetite schist, or TMS, layer; a concordant quartz-tourmaline, or QT, vein; and a discordant quartz-feldspar, or QF, vein.
This setting creates ideal conditions for the formation of emerald crystals, particularly large-sized crystals, Gemfields said.
In addition to the individual Imboo, Insofu, Inkalamu, and Chipembele emeralds, the Chama pit also produced the “Kafubu Cluster,” a group of emeralds weighing nearly 190,000 carats found in 2022.
In addition to coming from the same area of mine, the Imboo emerald shares another similar with the other large emeralds recovered from Kagem in the last 15 years—its name.
Imboo, pronounced “im-bow,” translates to “buffalo” in the local Bemba and Lamba dialects and continues Gemfields’ tradition of nodding to Zambia’s wildlife when naming exceptional emeralds, it said.
Insofu means “elephant,” while Inkalamu translates to “lion,” and Chipembele to “rhino.”
Gemfields said it named this particular stone with the buffalo’s “determination, endurance, sense of community, and, of course, its sheer size” in mind.
African buffalos, which are divided into four distinct sub-species, are about 4-5 feet tall and can weigh anywhere from 660 to nearly 2,000 pounds, according to the African Wildlife Foundation.
“In my 30 years at Kagem, I’ve rarely seen such a remarkable formation of large, high-quality crystals,” said Jackson Mtonga, the Kagem sort house’s grading manager.
“The immense size and nature of the crystal formation makes it fitting that this unique piece is given the name ‘buffalo,’ or ‘Imboo’ in our local languages. This is a true masterpiece carved by nature’s hand.”
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