KAGEM Mine in Ndola has announced the discovery of an "exceptional" 6,225-carat rough emerald, a piece that the company expects will yield a number of significantly sized cut gems.

The emerald was recovered during normal mining operations on February 5, this year and experts for Gemfields have been examining the piece to determine its value and significance before deciding upon its future.

According to a press release issued on Monday, Gemfields, the London-based gemstone producer which owns Kagem Mine said the rough emerald has been dubbed Insofu, which means elephant, in honour of the World Land Trust's Elephant Corridor Project and in consideration of the stone's unusually large size.

"This is a unique find," Gemfields chief executive said officer Ian Harebottle.

The Insofu displays wonderful colour and good translucency. Its sheer size, rich colour and fine protective biotite shell makes it difficult to see deep into the gem. However, all indications suggest that the core of the emerald is competent and that it should yield a number of cut gems of significant size."

Gemfields focuses on the consistent supply of what it describes asethically produced emeralds, which are mined under a rigorous set of standards in regards to fair trade, environmental, social and safety practices.

It states that it guarantees the provenance of every gem through a full disclosure and certification programme.

The largest uncut emerald believed to have been found was in Carnaiba, Brazil in 1974 and it was an incredible 86,136-carat natural beryl crystal.

The stone was eventually valued at US $1,120,080 while the largest emerald crystal ever discovered was 7,025 carats and was found in a mine in Colombia.