A Complete Guide from the Experts at Onestep Gems
Emeralds are beloved for their deep, vivid green hue and timeless appeal—but if you've ever looked into buying one, you may have seen descriptions like "oiled" or "treated with oil." At Onestep Gems, one of the most common questions we get is:
“Why are so many emeralds oiled, and does it affect the value?”
This article will walk you through everything you need to know about emerald oil treatment—how it's done, why it's used, and what it means when you see it on a gem certificate.
What Is Emerald Oil Treatment?
At Onestep Gems, transparency is key. So let’s start with the basics.
Emerald oiling is a traditional treatment method that involves using a natural oil—usually cedarwood oil—to fill surface-reaching inclusions (small internal fractures or fissures) in an emerald. This oil has a similar refractive index to the emerald, meaning it visually blends in, making the inclusions less noticeable.
The process looks like this:
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The emerald is cleaned.
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It’s placed in a pressurized chamber filled with oil.
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Gentle heat is applied to help the oil penetrate the fractures.
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After 12–24 hours, the emerald is removed, cleaned, and polished.
The end result? A brighter, clearer emerald that looks significantly better—but only temporarily.
Why Do Emeralds Need to Be Oiled?
Unlike diamonds or sapphires, emeralds are naturally full of inclusions and internal fractures—so much so that it’s expected and even accepted as part of their character.
However, too many inclusions can make an emerald look cloudy or dull. That’s why oiling is used to:
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Improve visual clarity
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Enhance light reflection
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Make the green color appear deeper
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Boost overall beauty for presentation or sale
That’s why over 90% of emeralds sold worldwide are oiled to some degree—even those in high-end designer jewelry.
The Hidden Truth: Why Oiling Lowers the Value of Emeralds
Here at Onestep Gems, we believe you deserve the full picture.
While oiling makes an emerald look better, it often means the emerald has more visible flaws than a similar untreated stone. Here’s how oiling affects value:
1. More Oil = More Inclusions
If an emerald absorbs a lot of oil, it likely has numerous open fractures or inclusions. These imperfections are a structural weakness and reduce the gem’s natural value. The oil just hides them.
2. Temporary Fix
Oil can leak out over time, especially with exposure to:
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Heat (jewelry repair, sunlight)
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Household cleaners or soap
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Ultrasonic cleaners
When the oil fades, the inclusions reappear, and the gem loses clarity. This means maintenance or re-oiling may be required to keep the stone looking its best.
3. Market Rarity
Untreated or minimally oiled emeralds are far rarer. Because they naturally have better clarity, they command higher prices and hold value longer—making them more desirable to collectors and investors.
Types of Oiling: What You’ll See on a Certificate
At Onestep Gems, all our emeralds come with certified reports detailing any treatments. Here’s how oiling is typically classified:
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No Oil (Untreated) – Extremely rare, most valuable.
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Minor Oil – Light inclusions, only slightly treated.
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Moderate Oil – Clearer appearance, but more flaws.
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Significant Oil – Heavily included emeralds with noticeable treatment.
When you shop with us, we’ll walk you through these differences so you can choose confidently.
Should You Avoid Oiled Emeralds?
Not at all. Even premium emeralds are oiled. The key is knowing how much oil has been used and what you're paying for.
At Onestep Gems, we recommend:
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Untreated or Minor Oil emeralds for collectors, heirloom pieces, and investment jewelry.
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Moderately treated emeralds for fine everyday wear at a more affordable price point.
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Avoiding significant oiling unless the appearance and price work for your short-term needs.
Final Thoughts from Onestep Gems
Emerald oiling is not a scam—it’s a widely accepted, centuries-old technique used to enhance a gemstone’s natural beauty. But like all gem treatments, it should be clearly disclosed, professionally certified, and fully understood before you buy.
When you buy from Onestep Gems, you get:
✅ Certified emeralds with transparent treatment reports
✅ Honest advice about durability and care
✅ A curated collection of emeralds with minor to no treatment
✅ Trusted service from gemstone professionals
Explore Our Emerald Collection
Ready to find the perfect emerald? Whether you're searching for an engagement ring, a collector’s piece, or a stunning birthstone gift, Onestep Gems is here to help you make an informed, confident purchase.
