How to Re-Oil an EmeraldHow to Re-Oil an Emerald

Emerald Specialist Mini Course

How to Re-Oil an Emerald

Question:Does anyone have any advice on how to re-oil emeralds? I recently had the misfortune of dopping an oiled emerald. The oil seeped out of the stone after being heated. I would really like to re-oil this gem. It looked great with the oil treatment. Can anyone help me?

Purchase Emerald Specialist Mini Course

Are you entranced by emerald greens? If this velvety gem draws your attention, you’ll love this course. Take an in-depth look at emeralds, from how they form to how to appraise them. Looking to buy or sell an emerald? Learn about treatments and evaluating emerald quality. Every emerald connoisseur will learn something new in this course.
Oiling is a standard industry practice for enhancing emerald gemstones. Most, but not all, emeralds receive oil treatments. These gems may lose their oil over time or by accident. However, it is possible to re-oil emeralds.
Oiling is a standard industry practice for enhancing emeralds. Most, but not all, emeralds receive oil treatments. These gems may lose their oil over time or by accident. However, you can re-oil emeralds. This emerald-cut emerald received a traditional oil treatment. © Dan Stair Custom Gemstones. Used with permission.

Answer: Before you re-oil emeralds, make sure you have actually removed all the old oil. You can do this by slowly simmering — not boiling — the stone in soapy water. Soaking it in a solvent like alcohol will also do the trick.

Emeralds almost always have inclusions. Some oil treatments try to make an emerald's jardin, or
Emeralds almost always have inclusions. Some oil treatments try to make an emerald's jardin (or "garden") of inclusions more visually pleasing. Oil treatments are also used to enhance color. Emerald ring, photo by Mauro Cateb. Licensed under CC By 2.0

To re-oil emeralds, all you need to do is submerge the stone in an appropriate solution (oil, epoxy, etc). Next, place the stone and the solution somewhere warm. The back of a stove or a sunny window in summer are great locations. Keep it at about 100° F for a day or two. That is all there is to it!

Sincerely,

Donald Clark, CSM IMG

Editor's note: You could also try this vacuum method for re-oiling emeralds.

emerald and diamond bracelet
Emerald and diamond bracelet, original design by Clarke Beattie. Photo by gemteck1. Licensed under CC By 2.0.

International Gem Society


Never Stop Learning

When you join the IGS community, you get trusted diamond & gemstone information when you need it.

Become a Member

Get Gemology Insights

Get started with the International Gem Society’s free guide to gemstone identification. Join our weekly newsletter & get a free copy of the Gem ID Checklist!