Today,
Gemfields, operator of the
Kagem mine in Zambia has announced the discovery of
"Insofu". Coming in at 6225
carats, Insofu is one of the largest (currently uncut) emeralds ever discovered (behind the
7025 carat Colombian emerald Emilia, and the very poor quality
1182 lb. Madagascar emerald). Insofu means elephant in the language of the
Bemba people who are indigenous to the area, and was named because of both its amazing size and in honor of the World Land Trust's
"Wild Lands Elephant Corridor Project" in India which Gemfields participates in.
Currently it is difficult to asses how many stones and of what size Insofu may yield. The stone has a fine
biotite shell, which produces a shiny surface. Too, it is of an unusually dark green color with a vivid hue produced by heavy concentrations of
chromium (making it a very valuable emerald indeed). All of these make it difficult to asses the internal structure and quality of the gem.
While the article, and many other sources, reference a 86136-carat
natural beryl crystal found in Carnaiba, Brazil in 1974, it is technically incorrect to compare it to the Insofu and the Colombian crystal. While beryl and emeralds are technically the same material, only stones with a deep green color and vivid hue are considered true emeralds.
Beryl ranges in color from pale blue-green to nearly yellow (and sometimes red and pink), but these other color variations do not fetch the same value as the deep green emeralds. When heat treated, blue-green Beryl is usually sold under the gem name of
Aquamarine.
posted by The Whelk at 12:53 PM on February 22, 2010 [11 favorites]