You oil emeralds by carefully applying a tiny drop of oil, typically cedar oil or a suitable alternative like baby oil, directly to the affected area and allowing it to penetrate the flaws.
Here's a more detailed explanation of the process:
Why Oil Emeralds?
Emeralds are known for their inclusions, often referred to as "jardin" (French for garden). These inclusions can sometimes reach the surface, making them more visible and potentially affecting the stone's appearance and durability. Oiling helps to:
- Reduce the visibility of inclusions: The oil fills the surface-reaching fractures and fissures, making them less noticeable by reducing the difference in refractive index between the emerald and the air within the inclusions.
- Improve clarity: By minimizing the appearance of inclusions, oiling enhances the overall clarity and brilliance of the emerald.
- Enhance color: The oil can subtly enhance the green color of the emerald.
The Oiling Process: A Step-by-Step Guide
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Choose the Right Oil:
- Cedar oil is the traditional and preferred choice due to its similar refractive index to emeralds and its stability over time.
- Baby oil (mineral oil) is a less expensive and acceptable alternative, although it may not last as long as cedar oil and might require reapplication. Avoid using vegetable oils, as they can become rancid.
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Application:
- Use a fine needle, toothpick, or the tip of a cotton swab to pick up a very small drop of oil.
- Gently touch the emerald only on the area with the surface-reaching inclusion or flaw. Avoid applying excessive oil to the entire stone.
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Waiting Time:
- Allow the oil to penetrate the flaw. The longer the waiting time, the better the penetration. A few minutes may suffice for minor flaws, but overnight is ideal.
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Removal of Excess Oil:
- After the waiting period, gently wipe away any excess oil from the surface of the emerald with a soft, lint-free cloth.
Important Considerations:
- Professional Oiling: While you can oil emeralds at home, professional jewelers have specialized equipment, such as vacuum chambers, to improve oil penetration.
- Disclosure: Ethically, sellers should disclose whether an emerald has been oiled.
- Treatment Permanence: Oiling is not a permanent treatment. Over time, the oil can dry out or be removed during cleaning or exposure to heat. Re-oiling may be necessary.
- Cleaning: Avoid ultrasonic cleaners and harsh chemicals, as they can remove the oil from the emerald. Use a soft brush and mild soap to clean oiled emeralds.
Conclusion:
Oiling emeralds is a common practice to improve their appearance and clarity by minimizing the visibility of inclusions. Applying a small amount of cedar oil or mineral oil to the affected area and allowing it to penetrate can effectively enhance the stone's beauty.
