(IDEX Online) - An auction billed as the "world's first" of rough tourmaline - the brightly-colored gemstone - is to take place in Bangkok in November.Iridis, new owners of the Jagoda mine, in Zambia, says it will showcase the largest collection of exceptional pink, green, and bi-color tourmalines.It also says it's using the first-ever tourmaline grading system for prospective buyers.Cyrille Djankoff, the company's CEO, said: "This forthcoming auction is the culmination of 18 months of production from our Zambia operations which will see these stunning gemstones in a first of its kind grading system with 100% traceability."Iridis says Jagoda, which first came on stream in 1997, was initially known for its exceptional pink tourmaline.But subsequent surveys by the GIA and others suggest it may prove to be one of the most important sources of tourmaline the world has ever known.Pic courtesy Iridis