Caring for Opals: Preservation & Measurement Guide

Question
Hi Steve,It's nice to find an expert to get the right answers from. This question consist of two parts. The first question that everytime I ask it , I get a different answer is: Is it better to put a good grade of oil on an opal to keep it from getting brittle or just plain water or nothing? I have my grandmother's opal engagement ring that is 108 years old and I want it to be passed down in the family so I want to take good care of it. 2nd part is : How do you correctly measure opals for settings?   Thanks for your expertise.     Nancy

Answer
Hello,

I keep my opal in water.  Oil does not evaporate as easy as water and could be good.  But water does work to store opal.  When you take it out
depending on the opal it could develop cracks overtime.  If your opal is old and it has not cracked then you do not have to worry as much.  The opal that does crack would have cracked by now unless it was stored in water.  I have seen lots of high grade opal that is old and is still good.  

I measure opal with a millimeter gauge.  Settings are measured the same way.

Hope this helps you,

Steven D.Covey