Back to IGS | FAQ | Contact

Emerald oiling


Hello everyone,

I hope you are doing well. I recently had some work done on a ring of mine, and unfortunately the jewel smith which did the work put my emerald into an acidic bath, and then also put it in an ultrasonic bath, so you can image what an oiled stone must look like now. I was in the process to beginning to re-oil the stone, when I couldn’t find any cedar oil, so that got me thinking what other alternatives do I have. I looked up colorless natural oils, and noticed that anise oil, which comes in a colorless form, has a refractive index of 1.54-1.56 which is MUCH closer to the refractive index of emeralds than cedar oil. That got me thinking, while I havent tried to oil the emerald with anise oil yet, what would be the reason that emerald treatment specialists havent used this type of oil as a treatment even though its refractive index is MUCH closer to emeralds than cedar oil. Does anyone have any information, or insights on this topic?


sorry have not idea in relation to oils for emerald, but must comment to say no jeweller in his/her right mind would put an emerald in an ultrasonic cleaner or a lot of other gemstones for that matter, I would not use this jeweller again for any reason.


This is an interesting question! One thing that comes to mind is the stability of the oils. Unfortunately, a quick google search doesn’t bring much information. This study shows that anise oil is at least somewhat sensitive to light, but general info pages on cedar oil say that it’s also sensitive to light. I’m not sure of the reaction times for decomposition. It could be that cedar oil lasts longer before noticeable chemical changes, but I haven’t found any information on this.

The difference in RI is unlikely to make a big difference, but if you’re looking for something closer in RI you could use Opticon. Also, cedarwood oil is available on amazon!

Also, I have to agree with SydP - emeralds can crack in the ultrasonic cleaner!

Geologist and IGS Team Member


I agree with you both. I wont be. I am going to try and salvage the emerald with oiling. The difference in RI will make a difference, it will completely disappear inside the stone. Yes, stability is a question. Opticon is resinous and will greatly decrease the value of the stone. Id prefer not to put opticon in it. I can actually see cracks in the stone now, they are surface reaching, but I am unsure if they were there before hidden by the oil, or if they are new. I personally tested the stone a few years ago before putting it aware in the safe. I guess ill find out when I soak it in acetone to remove the oil, and put the new oil in. If it falls apart, the cracks are new.


I have heard Steve Bennet of Gemporia ( say that baby oil is the one to use for emeralds. "Oiled or filled Emeralds shouldn’t be cleaned with an ultrasonic or steam cleaner. If your oiled Emerald is losing some of its liveliness, you can easily re-oil it at home. Place it in a shallow dish of lukewarm baby oil and leave it overnight. " from the Jewelry care pages.


Not much of a jeweler if he put your emerald into an ultrasonic cleaner but that has been stated. sells an excellent cedar oil. I have used opticon in stabelizing Turquoise and some opal cracks but never on emeralds before so I can’t vouch for the procedure. I do know that it is less likely to yellow over time in the smaller fissures than any other product on the market so far.
I hate to hear about someone damaging your stone. At least it did not fall to pieces.
All the best.