Emerald Oiling – The Pursuit of Perfection


o strive for perfection is only human nature, this is even more true when discussing gemstones! For millennia humans have been experimenting with ways to improve and perfect the rough jewels they have mined from the earth, and when it comes to emeralds the traditional method is through a process called oiling.

How long have we been oiling emeralds?

The idea of oiling of emeralds has been traced back as far as ancient Egypt, and is used to improve the clarity and sometimes the depth of colour within a stone. The process can take place both before or after the lapidary process to ensure a consistent finish across the gem.



Traditionally the favoured material for this process is cedar or Canadian balsam oils, today hard resins exist and can be used as an alternative, providing a more permanent solution. However, since cedar oil is natural, it’s the more sought after refining treatment should a gemstone need it.

Are there different degrees of treatment?

The LMHC (Lapidary Manual Harmonisation Committee) divides and classifies emerald treatments into five categories: No surface reaching fissures present, no oil/insignificant and then minor, moderate and significant treatment. As you progress through each category, the more fissures and surface reaching inclusions exist in the stone, which will require a higher level of treatment.



Unlike many other treatments, the process of oiling an emerald is reversible (whether by choice or accident.) But in a high paced world where people may not be informed of the special care required, why use such a sensitive treatment? Ultimately it has to do with the fact that oil has the unique ability to penetrate the narrow fissures and cracks within an emerald, easily creating a deeper and overall better looking stone.

Emerald Ring Portrait

Some things to remember about emeralds...

While untreated emeralds exist in the market today, they are exceptionally rare and expensive. Unless you are purchasing your jewel from a reliable source and documents are supplied (GIA, SSEF or Gubelin) to confirm a lack of treatment, it is always best to assume a treatment has occurred.


When you’re considering purchasing an emerald, it’s important to keep this information in mind; Emeralds are a soft gemstone in need of delicate wear, so it is important to remove them before washing your hands (or doing dishes) and when applying oils and creams. This will ensure that you won’t accidentally reverse any treatment or need to have your emerald professionally cleaned too often. It will also keep the stone safe so that it can be admired for many generations to come.


Thank you to my friend Carly over at St. Eloi Vintage for supplying me with this stunning antique emerald ring to photograph for this article. Although this piece is unsigned, its delicate claws, glowing emerald, and scintillating diamonds are a showstopper!