From NKWAME MARC in Arusha, 26th April 2011 DEPOSITS of tanzanite, a rare violet blue gemstone, only found at Mirerani in hills, Simanjiro District, Manyara Region, can last up to 100 years before they are completely exhausted, industry sources said. "With responsible mining and careful digging tanzanite deposits in the Mirerari hills can last over a hundred years," said Mr Wessel Marais, the Acting Chief Operating Officer of Tanzanite-One Limited. Mr Marais dismissed as false and unfounded claims that the rare violet blue gems would be exhausted within the next ten years. Tanzanite-One, he said, had been conducting series of surveys on the gemstones. He said from the surveys it was unlikely to find tanzanite deposits elsewhere in Northern Tanzania apart from Mirerani, but there were possibilities of finding other important minerals. Tanzanite, believed to be ten-times rarer than diamonds, may be elusive to some miners, but that does not mean they are about to be exhausted. Tanzanite-One Corporate Governance Manager and Company Secretary, Mr Lusekelo Mwakalukwa, said responsible mining can only be accomplished if artisanal miners and large scale operators would be working together. "There has been protracted animosity between small and large scale miners. Small scale miners regard Tanzanite as their enemy," Mr Lusekelo said. "As miners of the world's rarest gemstones we are faced with many challenges and have other major problems to address other than fighting ourselves. "Once united we can turn around the tanzanite industry into an international prestige, similar to what De-Beers and Tiffany have so far accomplished," said Mr Mwakalukwa. The tanzanite mining industry earns the country about 20 million US dollars (30bn/-) annually.