Possibly dumb question.

[Sparklelu]

Without a previous appraisal is it possible for a knowledgable jeweler tell where a gem is from? For example over 25 years ago my husband gave me a ruby and diamond ring. We got it from a well respected jeweler in NYC . He made a big deal at the time that it was a Burmese ruby. My question is can that be verified just by examining the stone? I can't upload from my iPad but I will try to find a link where I posted the ring one time.

 

[justginger]

Re: Possibly dumb question.

AGL will provide an origin report, but to the best of my knowledge it is only an opinion based on physical characteristics that may be unique to a particular area or mine. Others with more experience may know exactly how it works, but I do think sometimes the lab gemologists disagree and the origin is listed as the place the majority of them choose.

 

[T L]

Re: Possibly dumb question.

Without a previous appraisal is it possible for a knowledgable jeweler tell where a gem is from? For example over 25 years ago my husband gave me a ruby and diamond ring. We got it from a well respected jeweler in NYC . He made a big deal at the time that it was a Burmese ruby. My question is can that be verified just by examining the stone? I can't upload from my iPad but I will try to find a link where I posted the ring one time.

Only if there are tell tale inclusions specific to the origin in question. It doesn't matter where/when you bought it.

 

[chrono]

Re: Possibly dumb question.

Showing a picture, unfortunately, cannot tell anybody about the ruby's origin. It is certainly possible that a well experienced and knowledgable GG can give his best estimate of its origin, or a good lab like AGL, based on specific inclusions that are known to often be from a certain locale.

 

[Sagebrush]

Re: Possibly dumb question.

Elisateach,

Your question is not dumb at all. It is reasonably easy for an experienced gemologist to tell if a ruby is "Burma-type". Telling he actual area where the gem was mined is quite a bit more difficult though not impossible.

There are essentially two types of ruby available on the world market. For ease of description lets call them "Burma-type" and "Thai-type." or non-iron type" and "iron-type" because the presence or absence of iron is the defining characteristic. The presence of iron tends to reduce the saturation of color in gemstones. In ruby the presence of iron quenches the natural UV-fluorescence. In Burma-type low iron ruby, the gemstone fluoresces a bright red under ultra-violet light. Though we can't actually see ultra-violet fluorescence, its presence supercharges what we do see, that is the red. The same is true in diamond. What we know today as a blue-white diamond is a gem that fluoresces blue in UV. We don't see the UV, but what we do see appears to be a whiter white.

Ruby today comes mostly from Burma and Mozambique. There is some material dribbling out of Tanzania and a tiny bit from Sri Lanka but not much. Both types of African ruby and Sri Lankan ruby contain iron and do not fluoresce in UV. Burma-type has been found in Burma, Vietnam, Pakistan and Afghanistan. Not surprising given the overlapping geology of that region. In some of the Vietnamese material, long mined out, the fluorescence actually lapped over into the visible spectrum, making the stone seem to vibrate and glow.

Differentiating origin between rubies found in Pakistan, Burma and Vietnam is difficult requiring a specialist knowledge of the types of inclusions native to each specific geological area and, quite frankly, from the point of view of beauty, that does not matter very much.

Hope this helps.

RWW

 

[minousbijoux]

Re: Possibly dumb question.

Where would Thai rubies fit in? I thought that they contained iron as well?

 

[Sagebrush]

Re: Possibly dumb question.

Minous,

Thai rubies do contain iron. I did not mention them because production all but ceased some years ago. Until the reintroduction of Burma ruby in the early 1990s when the junta opened the gem fields and the Mong Hsu diggings were discovered, Thai ruby was the standard bearer. That is why I used the term "thai-type" because the grading of ruby quality was based on the best of the Thai production.

In the early 1980s I would celebrate if I could find one Burma ruby worth purchasing in Bangkok. Most jewelers were unfamiliar with Burma ruby and when they first hit Tucson in force a lot of jewelers were reluctant to purchase them, obviously that didn't last long.

RWW

 

[Sparklelu]

Re: Possibly dumb question.

Thank you all for your kind replies especially Richard. I knew nothing about jewelry back then except ooohhhh pretty. Now that I have found PS I am curious -and wish we had more info on that ring and a few other pieces. Some day I suppose I will bring them to a he plots for a thorough look over. I do know when I had it razed years ago, the jeweler mentioned that it was a good quality stone.. Or given what Richard said about fluoro I might have to remember to wear my ring on Buzz Lightyear at Disney World! My five stone does some neat stuff in there!!! again thank you all. I love PS for the wonderful folks!