TanzaniteOne Limited said it has unearthed the third-largest high quality gemstone ever mined in the decade that it has been operating. March 02, 2011 TanzaniteOne Limited said it has unearthed the third-largest high quality gemstone ever mined in the decade that it has been operating. The 12,100-carat tanzanite stone, weighing 2.42 kg, was discovered at the firm's main tanzanite project in the Simanjiro district of Tanzania. It is believed to be the third-largest tanzanite ever found, and the stone is undergoing analysis, including colour and clarity grading. The stone is likely to be cut into smaller, but nonetheless large stones, at the firm's own cutting facility at the TanzaniteOne mine site. TanzaniteOne's CEO Bernard Olivier said, "Whilst we await the results of expert analysis on this significant discovery, we will continue to realise the potential of our mine, which produced a total of $15.8 million in sales for 2010." Meanwhile, in separate news, TanzaniteOne said it achieved its annual production target of 2.2 million carats in 2010, up from 1.9 million carats in 2009. The average grade was 59 carats produced per tonne, compared with 51 carats per tonne in 2009. The company is also continuing to hold talk with the Tanzanian government over a ban on the export of rough tanzanite weighing more than five carats which came into effect on December 31.