What is "Oil" in Emeralds?

Understanding the meaning behind one of the the biggest terms in the emerald industry.

Why it Exists

Emeralds are known for their rich green color and natural inclusions.

Emeralds often bear surface fractures, and these are commonly treated and filled with substances such as oil, wax, resin, or other materials.

This treatment is applied to enhance the clarity of the emeralds.

In this article, we will explore what emerald oiling is, how it impacts emerald quality and price, and why transparency in gemstone transactions is crucial.

What is Emerald Oiling?

Emerald oiling is a common treatment process used to enhance the visual appeal of emeralds. It involves filling surface-reaching fissures or fractures within the emerald with colorless substances, such as cedarwood oil or colorless resins.

By filling fissures and other inclusions within the Emerald, oil treatment can improve the emerald's clarity, color, and overall transparency.

Why are Emeralds treated with oil?

The primary goal of emerald oiling is to enhance the quality and beauty of the gemstone. Filling the fissures and fractures makes the emerald appear clearer and more vibrant. This enhancement can significantly improve the overall beauty of the emerald, making it more attractive to buyers.

Are there levels to oil treatment?

Emeralds can exhibit a wide range of oil treatments, which significantly impacts their quality and price. Some emeralds are found with no oil treatment, retaining their natural characteristics, while others may have only insignificant or faint levels of oil.

These lightly treated emeralds are highly valued for their minimal intervention and illicit a closer connection to emeralds in their natural form. Few emeralds fall into the category of having minor amounts of oil, striking a balance between enhancement and preserving their inherent beauty.

On the other hand, commercial-grade emeralds often undergo moderate to major levels of oil treatment to improve their visual appeal, making them more accessible in terms of affordability while still possessing captivating green hues. Buyers should be aware of these varying treatments to make informed choices when acquiring emeralds, considering their personal preferences and the importance of transparency in the gemstone market.

How does Emerald oil affect price?

Untreated emeralds displaying exceptional beauty without the oil treatments that have become ubiquitous in the world of emeralds hold a unique position in the world of gemstones.

Their value is often significantly higher than their treated counterparts due to their purity and scarcity in the market. These untreated emeralds are a testament to the raw and unaltered beauty of nature, making them the most sought-after and valuable emeralds in the gemstone industry.

While treated emeralds are more readily available and affordable, it is the unadulterated, high-quality, and untreated emeralds that capture the hearts of collectors and connoisseurs, making them prized possessions that transcend trends and generations.

GIA's Levels To Oil Treatment

NONE (Untreated)

GIA, GRS, AGL , and SSEF stand as some of the most esteemed gem labs worldwide. While they employ varied terminology to classify levels of oil treatment, the essence remains consistent across all.

How can I be sure to buy the right Emerald?

In the world of gemstone trading, transparency is essential. Buyers should always be informed about any treatments that an emerald has undergone. Gemological laboratories, such as the Gemological Institute of America (GIA), the American Gemological Lab (AGL), and Swiss Gemmological Institute (SSEF) issue reports that specify whether an emerald has been treated, helping buyers make informed decisions about their purchases.

Reputable jewelers and gemologists play a crucial role in ensuring transparency and helping buyers understand the true value of their emeralds.


Emerald oiling is a widely accepted practice in the gemstone industry, aiming to enhance the appearance of emeralds and make them more appealing to buyers. While treated emeralds are more budget-friendly, the unadulterated beauty of untreated emeralds, with their rarity and natural allure, remains unparalleled. Always work with reputable sources when buying or selling emeralds to ensure you are making informed choices and obtaining the best value for your investment.