ZAMBIA (BERNAMA) - A one-of-a-kind, 5,655-carat emerald crystal weighing a whopping 1.1kg has been discovered in Zambia, Gemfields announced on Monday (Oct 29).

The London-based supplier of sustainably sourced gemstones described the precious jewel as having "remarkable clarity and a perfectly balanced golden green hue".

The crystal was unearthed in October in Kagem, the world's largest mine, which is 75 per cent owned by Gemfields and 25 per cent owned by the Zambian government's Industrial Development Corporation.

It has been named Inkalamu (which means lion in the local Bemba language) in honour of the work carried out by two of Gemfields' conservation partners, the Zambian Carnivore Programme and the Niassa Carnivore Project in Mozambique.

"The naming of uncut emeralds is a tradition reserved for the rarest and most remarkable gems," said the company in its announcement.

"While no official records exist, perhaps two dozen have merited their own name and with the majority weighing less than 1,000 carats. Gemfields last named an emerald in 2010 when it unveiled the Insofu or Elephant Emerald."

The Lion Emerald will be auctioned in Singapore in November to about 45 partners selected for their "shared values in responsible practices", said Gemfields.

It added that in contrast to the diamond industry, the price for exceptionally large emeralds like Inkalamu is particularly difficult to predict.

Gemfields managing director for product and sales Adrian Banks said: "We expect a number of large, fine-quality cut emeralds to be borne of the Inkalamu crystal."

These important pieces are what return value to the buyer, and there might be hundreds of offcuts that are fashioned into smaller gems, cabochons and beads. But the key lies in recovering the fine quality pieces.

"Given this emerald is such a rare find, it is also perfectly conceivable that the buyer will choose to purchase it as an investment," he said.