Home Emerald What Does Oiled Emerald Mean?

What Does Oiled Emerald Mean?

by Madonna

Emeralds, renowned for their vibrant green color and captivating beauty, have fascinated humans for centuries. However, many people may not be aware that most emeralds undergo a treatment known as oiling to enhance their appearance. This article delves into the concept of oiled emeralds, exploring the reasons behind this practice, the methods used, and its implications on the value and care of emeralds. By understanding what oiled emeralds mean, gemstone enthusiasts can make more informed decisions when purchasing and caring for these precious gems.

Understanding Emeralds: A Brief Overview

Emeralds are a variety of the mineral beryl, colored green by trace amounts of chromium and sometimes vanadium. They have been prized since ancient times for their lush green color, symbolizing renewal and growth. However, emeralds are often included, meaning they have internal fractures and impurities. These inclusions, sometimes called “jardin” (French for garden), are characteristic of natural emeralds and can affect their clarity and durability.


The Purpose of Oiling

Enhancing Clarity and Appearance

The primary purpose of oiling emeralds is to improve their clarity and overall appearance. Inclusions and fractures can detract from the gem’s beauty, making it appear cloudy or dull. By filling these fissures with a colorless oil, typically cedarwood oil, the transparency and luster of the emerald are enhanced. This treatment can significantly increase the visual appeal of the gemstone, making it more desirable in the market.


Stabilizing the Gemstone

Oiling also helps stabilize emeralds, which are relatively brittle compared to other gemstones like sapphires and diamonds. The internal fractures can weaken the structure of the emerald, making it more susceptible to damage. The oil acts as a filler, reducing the risk of chipping or breaking by providing additional support within the gemstone.


The Oiling Process

Types of Oils Used

Various oils can be used to treat emeralds, with cedarwood oil being the most common due to its refractive index, which closely matches that of emeralds. This similarity helps the oil blend seamlessly into the gem, making the treatment less noticeable. Other oils, such as palm oil, synthetic oils, and even resins, may also be used, but these are less common.

Application Methods

The oiling process generally involves the following steps:

Cleaning: The emerald is thoroughly cleaned to remove any dirt, debris, or previous treatments. This ensures that the oil can penetrate the fractures effectively.

Heating: The emerald is gently heated to open up the fractures, making them more receptive to the oil.

Immersion in Oil: The emerald is then immersed in the oil, allowing it to seep into the fractures. This can be done at room temperature or under vacuum conditions to enhance penetration.

Cooling and Drying: After sufficient time, the emerald is removed from the oil and allowed to cool and dry. Excess oil on the surface is wiped off.

Duration and Frequency

The oiling process can take several hours to a few days, depending on the size and condition of the emerald. While the treatment is not permanent, it can last several years. Over time, the oil may dry out or be washed away, requiring re-oiling to maintain the gem’s appearance.

Evaluating Oiled Emeralds

Disclosure and Certification

When purchasing an emerald, it is crucial to inquire about any treatments it has undergone. Reputable dealers should disclose whether an emerald has been oiled and provide a certificate from a recognized gemological laboratory. This certificate will detail the type and extent of the treatment, helping buyers make an informed decision.

Grading and Value

The presence of oil in an emerald can affect its value. Natural, untreated emeralds with high clarity and color are rare and command premium prices. Oiled emeralds, while still valuable, are generally priced lower than their untreated counterparts. The extent of the treatment also plays a role in determining value. Emeralds with minor oiling are more desirable than those with extensive treatment.

Caring for Oiled Emeralds

Avoiding Harsh Conditions

Oiled emeralds require special care to maintain their appearance. Exposure to harsh chemicals, extreme temperatures, and ultrasonic cleaners can remove the oil and potentially damage the gemstone. It is advisable to clean oiled emeralds with mild soap, warm water, and a soft brush. Avoiding prolonged exposure to direct sunlight and sudden temperature changes can also help preserve the oil treatment.


Over time, the oil in an emerald may dry out or be washed away, necessitating re-oiling to restore its clarity and luster. This process should be done by a professional jeweler or gemologist to ensure the gemstone is properly cared for and retains its beauty.

Ethical Considerations

Transparency in the Market

The practice of oiling emeralds has raised ethical considerations within the gemstone industry. Transparency is key to maintaining consumer trust. Reputable dealers and jewelers should clearly disclose any treatments, including oiling, to buyers. This allows consumers to make informed choices and understand the true nature of the gemstones they purchase.

Sustainable Practices

As with all gemstone treatments, the environmental impact of oiling should be considered. Using natural, sustainable oils like cedarwood oil is preferable to synthetic alternatives. Additionally, the gemstone industry is moving towards more environmentally friendly practices, including ethical sourcing and responsible mining.

Alternatives to Oiling

Resin Infusion

In addition to oiling, resin infusion is another treatment used to enhance the clarity and stability of emeralds. Resins are more durable than oils and can provide a longer-lasting solution. However, this treatment is more permanent and may affect the gemstone’s value differently compared to oiling.

Non-Treated Emeralds

For collectors and enthusiasts seeking untreated gemstones, non-treated emeralds are available. These gems, while rarer and often more expensive, offer a natural, unaltered beauty. When purchasing untreated emeralds, it is essential to obtain a certificate of authenticity from a reputable gemological laboratory to verify the gem’s natural state.

See Also: Does Wearing Emerald Gemstone Help You to Pass Exams?

Oiling in the Gemstone Industry

Common Practice

Today, oiling is a common and widely accepted practice in the gemstone industry. Most emeralds on the market have undergone some form of oil treatment. This practice helps make emeralds more affordable and accessible to a broader range of consumers, without significantly altering their natural beauty.

Industry Standards

The gemstone industry has established standards for disclosing treatments, including oiling. Reputable gemological laboratories, such as the Gemological Institute of America (GIA) and the American Gemological Laboratories (AGL), provide detailed reports on gemstone treatments, ensuring transparency and consumer confidence.


Oiling is a widely used and accepted practice that enhances the clarity and stability of emeralds. By understanding what oiled emeralds mean, consumers can make informed decisions when purchasing these captivating gemstones. While oiling does not diminish the natural beauty of emeralds, it is essential to be aware of the treatment, care for the gemstone properly, and seek reputable dealers who disclose all relevant information. With proper care and consideration, oiled emeralds can continue to dazzle and enchant for generations to come.


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