Everlasting Emeralds

HeLLO! travels to the world’s largest opencast emerald mine, Gemfields’ Kagem, in Zambia and comes away bedazzled.

The UK-based jewellery brand, Gemfields, is widely considered to be the largest producer of responsibly produced and distributer of coloured stones. Traditionally, the coloured stone industry lacked scale and systematic approach, but Gemfields has dynamically changed this. The Kagem emerald mine, located near the city of Ndola, is a world-class operation supplying about one-third of the global production of emeralds. The operation encompasses processing, sorting and grading, tied to Gemfields’ auction systems for direct mine to market supply chain.

For the uninitiated, Gemfields acquired the mines from the government in 2008 and by 2009, had converted the mines into a profit making, tax paying entity, providing 3.5 million injury-free shifts for its workforce and long-term CSR strategies.

Now the emeralds from Zambia differ from those of their counterparts as they are formed from different rock types, hence being richer in iron and greener in colour. Talc-magnetite schist provides the emerald’s key element of chromium, while the pegmatites provide the beryllium. The reaction between these two layers with the right temperature of 590-830 degrees and pressure of 400 – 800 MPa, are key for the emerald producing zones.