Opaque emerald setting


I’m to set an oval emerald (a fairly pale and cloudy stone)
17mmx21mm in gold. Usually, I secure creations in setting wax to hold
them steady while I work on getting the setting done.

My question is:- Is the hot setting wax going to be too much (too
hot) for a stone which generally doesn’t like heat?

If yes, then how can I hold the stone whilst doing the setting?!

Thanks in advance,