There are some real horror stories out there. I will give you a link to one. Meanwhile, here is what one appraisal firm says in their FAQs:
“Do I need to leave my jewelry?
No, you don’t have to leave your jewelry and we don’t remove any stones for the appraisal. Most of the time we take photographs and specifications of your jewelry while you wait. You take your jewelry with you and we finish the appraisal after you leave and mail it to you. For many items you can take the appraisal with you as well.
Do you remove any stones from the jewelry for the appraisal?
Never. No stones are removed, ever. Weights are estimated using available measurements and accurate weight estimation formulas. These methods get very close to the true weight, but any certificates you have on any of your jewelry will be very helpful in reducing estimation error caused by the mounting.”
Never have an appraisal done by someone who buys and sells gems.
Here is the horror story link. Please don’t let them take your stone out.
Good luck!