Sizing Tanzanite ring...

[conitta]

I have several Tanzanite rings that need to be sized. One is the first piece of Tanzanite jewlery I bought, several years ago. I have been wearing a ring sizer on the back because I am scared to have it sized. Now I have 2 more to size. My question is...do you have to take the stone out? I fear scratching the stone in this case. Also, I was told there is something that you put on the stone to protect it from the heat. Just don''t want anything to happen to my Tanzies...Please advise. Thank you...