Hello,

As a trainee, I sometimes wonder about advanced issues....The latest quandry I have is about accidently heating a gemstone.

If I were to say, leave a Sapphire or an Emerald or even an Onyx in a setting as I expand or anneal a ring and the stone were to change colour, how can I get the stone to return to its normal colour ? Is there a shock treatment or another old fashioned way to un-darken a stone ?

I ask as I was playing with a synthetic Sapphire today and the thought crossed my mind.

Thank you in advance