Color change tourmaline

I have a large 49.1 ct color change tourmaline. Info on such a rare gemstone is scarce at best. I would appreciate it if you can share information on the topic i.e. Where are they found and what are they valued at. Any other knowledge you can share on this topic is also appreciated.

Thanks,

Chris


Hi Chris big gemstone, have you tested the RI and SG to confirm it is Tourmaline??
where did the gemstone come from how did you get it??

thanks

Thanks for your reply Syd. I inherited it from my uncle. He bought it in India from a trusted source while on one of his six world wide gem safaris he made while he was still alive. The SG checks in at 3.1 and it’s highly dichroic. I do not have the equipment to check out the RI however. I only started to take interest in the world of gemstones after receiving over 250 gemstones from him after his death 3 yrs ago.
Any other info you or any of colleagues can give me would be appreciated.

Thanks again,

Chris

Hi Chris, well I have found a few items that do talk about colour change tourmalines but you are right very little is written that I can find I have attached these abstracts and websites for your info