Quality of emerald

[Roselina]

Dear coloured gemstones lovers

It's a frist for me. I always wanted an emerald and I always wanted a toi et moi ring. When I saw this one in an online auction, I grabbed it right away. ...without knowing about the quality of the stone. For the price I thought it was ok plus I could tell that the diamond was nice and the price would be ok for the diamond alone. However, knowing so little about emeralds I thought I come here and ask. Is anyone able to tell if the stone is ok? You can be honest, I know that online buys can be tricky and I can live with it. I ask because I plan to reset the stones in a yellow gold toi et moi setting and want to know if it is worth it or if I should look for another emerald. I assume the stone is treated (as most are) - however, I wouldn't know exactly and not if heavily or not. Is there a way to find out?

Thank you so much!

 

[LilAlex]

No way to know. Pretty hue and nice shape and crisp facet lines on the crown so, based on the last, I infer it is not old. And if it's not old and it has such prominent inclusions/fractures (some look like they are nearly half the diameter of the stone), I infer that it is heavily treated and was not great starting material. All of this could be completely false.

I like the white metal. Could be risky to re-mount that emerald.

I would not buy an emerald without a reputable report. Well, I did a long time ago but I would not now..

 

[Roselina]

Thank you so much for your reply. I'm outside the US and it is very rare to find stones on the second hand market with a certificate. It's still not very common here. However, we do have a little lab here in town and they do test. I might go there and give it a try. I won't be sad, if it's (heavily) treated. I bought it because it looks pretty. However, I might then look for another emerald to complete my idea of a toi et moi.

 

[Avondale]

Oh, this is such a lovely colour in sunlight!

If what you paid more or less covers the diamond alone, I wouldn't expect the emerald to be of particularly high value. It would be a nice surprise if it was, though. It's impossible to tell from a picture. You would need to have the stone examined by a person or a lab who can identify both the type and level of treatment (GIA, for example, only states level of treatment, but not type). Origin, too, if that matters to you.

Regarding treatments, with emeralds these are mainly clarity enhancements. I'm not sure whether humanity has yet found a way to permanently improve an emerald's colour, but sometimes people do dye them. All clarity enhancements involve a substance penetrating the stone through open fractures and thus masking them and making them basically invisible to the naked eye.

First, you have the traditional clarity enhancement which is cedarwood oil. It's transparent and it's been used for so long, it has basically become the norm. Cedarwood oil is not permanent. On one hand, it can easily be removed, the stone can be cleaned. On the other, since it's a natural substance, over the years it will dry out. In any case, the result is that the stone's inclusions will become more visible and prominent.

Second, you have the more modern and stable enhancements which use epoxy resins. I don't know much about them, only that they supposedly last a lot longer than oil.

The level of the enhancement is usually categorised as minor (F1), moderate (F2) and significant (F3). This gives you an idea of not only how much added substance there's in the stone, but also of the emerald's actual clarity. The less surface reaching fractures there are, the less oil/resin will be able to penetrate into the stone. If there are no surface reaching inclusions at all, it will be impossible to apply a clarity enhancement.

Regarding resetting the emerald, you'll have to get the qualified opinion of a jeweller. Emeralds in general are fragile, and the more fractured and included they are, the more there's a risk that they may chip or straight up shatter during resetting. On the other hand, with that missing prong, you don't have much choice in the matter, it will have to undergo some work, even if you were to wear the ring as is.

 

[Roselina]

Thank you Avondale for your thoughts. It might be best to just bring it to a reputable jeweller. The one I usually work with does have a gemologist, even though they don't do certificates. But to know if it is worth to remount (and the risk of breaking it) could possible be estimated. I'll come back as soon as I have news .

 

[RRfromR]

@Roselina , I'm struggling with the same thing! I'm in a decent sized US city and nobody can really tell me about emerald treatments. It seems that the technology needed to decipher the treatment is very costly. In addition, two of my most trusted antique jewelers refuse to touch pre-owned emeralds, due to liability. Mine is in a bezel, so they both refuse to even size it down. I really like yours - it has such a pretty color and clarity.

 

[Roselina]

Thank you, @RRfromR! I do like the colour as well. I mostly just shop by eye. Sometimes I win, sometimes I loose .