Technological Exploration of Heat Treatment and Spectroscopic Characteristics of Tourmaline from Keketuohai,Xinjiang

Heat treatment on Fe-Li tourmaline from Keketuohai,Xinjiang,are carried out and the main colour-altered technology parameters are obtained,including the experimental temperature,the atmosphere,the holding time,the velocity of heating and cooling during the heat treatment.Contrasting the effect of colour alteration at different stages,part samples show great improvement in colour and transparency.The appearances of dark-green and yellow-green samples become better respectively subjected to 550～650℃ and 650℃ in oxidative atmosphere,with obvious improvement on transparency.The colour of yellow-brown sample becomes yellow-green from weakening of the brown hue subjected to 650～700℃ in reducing atmosphere .Synchronous IR absorption spectra and UV-Vis transmission spectra are tested for verifying the results of colour alteration of the samples .