Abstract
Recently Spinel seems to become more popular in the market. It may be because there come beautiful color Spinels, not only red nor hot pink ones but also bright blue ones from Vietnam and others. Natural blue Spinel is known to be colored by iron and cobalt. (Mitchell, 1977) In the market such as Tucson gem show 2011, many nice blue Spinel were sold as "cobalt Spinel" without gemmological testing. We tested 44pcs blue Spinels (Tanzania 19pcs, Vietnam 11pcs, Sri Lanka 10pcs, Madagascar 1pc and synthetic 3pcs) with UV-visible spectrum and EDXRF, and 22pcs of them with additional LA-ICP-MS to detect its color mechanism.
