Refractol

[7188429]

I've come to see that some cutters use Refractol to examine rough gems due to it's R.I. I really wonder and would like to know if it would be fine to put for example a rough Emerald (no oil) into a jar of Cedarwood oil for inspection of inclusions based on the R.I. comparison? I know that Emerald's are often treated with Cedarwood oil which will come up as a grading result on a grading report but how does it differ from inspection to oiling?

 

[Seaglow]

The oil actually hides inclusions rather than show it, so not a good idea to put an untreated one in oil, especially prior to cutting. This is one of the reasons emerald is tricky to cut, apart from being usually a highly included stone, when a rough is oiled, you cannot see the inclusions/breaks and the stone can just shatter when cut. If you want to see inclusions, there is a special pen light that cutters use to select rough, and it is the mastery of using it that would let you see inclusions. Many times, a stone may appear 'clean' only to end up with an inclusion smack in the middle when cut.

 

[7188429]

That's what I assumed too.. But in regard to the Refractol, won't this "stain" other gems with oil too or is this just an issue with Emerald's?

 

[Seaglow]

Refractol is good for low RI stones, and useful for quartzes and it is easier to detect color zoning with it. But my comment was based solely for emerald, though Refractol can be useful in beryl. I guess you can take it out prior to cutting. I know some cutters who use acetone to take out oil.

 

[PrecisionGem]

Refractol is often used to evaluate inclusions in rough stones. The stone is dipped into the liquid which helps you to see into the stone and view feathers, views or other inclusions that would be very difficult to see otherwise due to rough outside surface of the stone. Baby oil is often used with emeralds for this purpose, and very often when buying rough emeralds they are still wet with baby oil on them. Since the refractive index of the oil and refractol is not too high, it is most useful on stone with lower refractive indexes such as quartz, aquamarine, emerald etc, although it does help with other stones. Once the stone is dipped in the liquid, the outside becomes almost invisible, and you can clearly see into the stone. When emeralds are treated with oil, they are most successfully done in a vacumm chamber where the oils is sucked into the stone. It is possible that dipping a stone in oil to examine it could leave traces of oil in the stone if it had very open inclusions that didn’t cut out, and these could show up in a lab report for treatment, even though the stone wasn’t properly treated after cutting with oil.

 

[Seaglow]

Refractol is often used to evaluate inclusions in rough stones. The stone is dipped into the liquid which helps you to see into the stone and view feathers, views or other inclusions that would be very difficult to see otherwise due to rough outside surface of the stone. Baby oil is often used with emeralds for this purpose, and very often when buying rough emeralds they are still wet with baby oil on them. Since the refractive index of the oil and refractol is not too high, it is most useful on stone with lower refractive indexes such as quartz, aquamarine, emerald etc, although it does help with other stones. Once the stone is dipped in the liquid, the outside becomes almost invisible, and you can clearly see into the stone. When emeralds are treated with oil, they are most successfully done in a vacumm chamber where the oils is sucked into the stone. It is possible that dipping a stone in oil to examine it could leave traces of oil in the stone if it had very open inclusions that didn’t cut out, and these could show up in a lab report for treatment, even though the stone wasn’t properly treated after cutting with oil.

Thanks for the info! I see many local cutters in source countries use baby oil to clean dop, almost for all stones. If it's ok, what do you think is the best way to clean dop after cutting? What I do is if baby oil was used, I soak stones in acetone.