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Oil or colorant

HI, i just want know if this is colorant or oil ?

Thanks for the help

I suspect this is a view from a microscope in darkfield illumination?
Emeralds contain inclusions that are very thin breaks that will reflect the stones color depending on the light’s path and the angle viewed.
So it could well be that it’s neither oil or colorant, but a simple reflector.

There are other tests to confirm colorants or resins.


yes is with microscope and darkfield.

What is the test i can do ?


I would explore your continued excellent observations with the microscope and try more techniques like using a diffuser plate, or try fiber optics (to aim light from various angles), immersion cells can also be very revealing. With some of these other methods also remember to tilt or rotate the stone while viewing to see if some of those color reflectors disappear, or if you see any single color flash effects from the cavity. Flash effects are indicators of fillers, but you have to know how to ID this flash effect correctly. If you are still convinced you may have oils…

The use of some stronger (LED type) long wave UV light sources aimed at those areas can also help ID. Oils and resins will fluoresce a whitish yellowish-green, as is their nature.

To be honest, I don’t see colorants used very often these days, it’s mostly just various clear fillers for clarity enhancement. They try to keep the oils or resins as invisible as possible. However, if you have very LOW grade emeralds, color and clarity enhancements are always a possibility.

I buy this emerald because i want see more enhancement for only 5$ i know is not a good stone and i wnat see what is it realy i check with refractometer is emerald with chelsa filter is turn red but when i check it i don’t think is natural and i try see what is the enhancement

Here a picture on sun light

for me that is a synthetic flux melt grown emerald … the above picture might show some remaining solution from the growing process (flux) … is it whitish and translucent/opaque ?