Gemfields has announced the discovery of Imboo, an extraordinary 11,685-carat emerald unearthed at its Kagem mine in Zambia — the largest exceptional stone ever recovered from the site. The gemstone will headline the company’s premium emerald auction in Bangkok, scheduled from 25 August to 11 September 2025.
Weighing 2,337 grams, Imboo showcases a rich green color enhanced by golden undertones. “Even when viewed under the strong lighting required to illuminate such a monumental stone, Imboo radiates an intense green glow with golden warmth and striking clarity,” noted Adrian Banks, Gemfields’ Managing Director – Product and Sales.
Banks added that the emerald could potentially yield multiple high-quality cut gems of impressive size, making it suitable for an entire high-jewellery suite. “This extraordinary find could be treasured both as a source of rare gemstones and as a lasting investment that will hold its place in the history of exceptional emeralds,” he said.
The stone, discovered on 3 August in Kagem’s Chama pit, follows the mine’s tradition of naming significant emeralds after African wildlife — previous finds include Insofu (elephant, 2010), Inkalamu (lion, 2018), and Chipembele (rhino, 2021).
To ensure full traceability, Gemfields will offer Provenance Proof nanoparticle tagging, which remains intact even after the gem is cut and polished.
“In my three decades at Kagem, I have rarely witnessed such a spectacular crystal formation,” said Jackson Mtonga, Grading Manager at the mine. “Its immense scale and character make ‘Buffalo’ — or Imboo in our local language — a truly fitting name. This emerald is nature’s masterpiece,” he concluded.