Home > Knowledge Posts > No Oil Emeralds – What Does it Mean

Why Are Emeralds Oiled

Emeralds are known to have a lot of inclusions inside the stone, features, such as fluid and solid inclusions and fissures, known as ‘the garden’ of emeralds. Most Emeralds especially from Colombia have lots of garden like inclusions.

Emerald inclusions which reach the surface are usually treated with oil that fills and ‘heals’ the small cracks which enhance the clarity and can also enrich the colour. They can be filled to a small or larger degree.

When a Lab report States no indications of clarity modification in fissures or no enhancement this means NO OIL or any other treatment, the emerald has not been treated or enhanced in any way completely natural how it was found.

Lots of natural Inclusions

A close up of a included emerald, with lots of liquid inclusions and crystals

Before and After

Left side : Cleaned with no oil. Right side: Oil then added Image by L. Phan, SSEF

The difference

As you can see from the above image, when an emerald is oiled it can change the whole appearance of the stone and sometimes change the colour. For this reason No oil or any treatment in an emerald is so rare and when one finds a no oil emerald of good clarity and colour it’s incredible and sought after the most serious Jewellery or gem collectors.

Treatment Class for emeralds

This can vary for each country and laboratory.

As an average these are the three classes of emeralds treatments

1.No Indications of clarity modification – This shows no oil or any enhancement – Nothing has been changed – no oil has been found.

2. Minor – Very small amount of oil, doesn’t change the appearance to much.

3. Moderate – fissures present have a noticeable, but not extreme, effect on the face-up appearance of the emeralds.

4. Significant – Very obvious effect on the face-up appearance of the emeralds, which means it looks a lot different before the filler was used, a very included stone.

Surface-reaching fractures in emerald are sometimes filled with essential oils, other oils, waxes, and “artificial resins”

Minor Oil Emeralds

This group you start to see more in emeralds they are still rare for a good colour and clarity.

The Emerald stones in the minor category often require a tiny amount of oil to make them reach their full potential and they are not t hiding any big cracks and only few fissure

These emerald of good overall grade demand high prices

No Indications of clarity modification - No Oil Emeralds

This is the rarest of all.

For emerald of this class they will need a certificate from a recognised laboratory to confirm the emerald has no oil as they are very hard to prove without scientific equipment.

Especially for any emerald over 1 carat of good colour and clarity.

Here at Jewellery Discovery we have a few very rare no oil emeralds from 2 carats, 6 carats and up to 8 carats which we may never see again.

No Oil emeralds are extremely desirable, prestigious and collectable.

The old mines of Colombia were known for producing the best quality emeralds stones that would not require any enhancements. These old mines have long gone and the old material is know mostly seen in antique jewellery.

No Oil Emeralds

No Oil Colombian Emerald And Diamond Ring