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Gem Certificates: When and When Not

Posted by Yvonne Raley on

Last week I got asked again if I provide gem certificates with my stones.  Customers want to know this periodically, so let me share my thoughts on this.

Who certifies gems?  There are several recognized gemological labs in the U.S. The best known is GIA, and their main gem of expertise is diamond, but they also certify colored stones.  Other known labs are: American Gemological Laboratory (AGL), American Gem Trade Association (AGTA), and Gemological Appraisal Laboratory of America (GEMLAB).  All of these have locations in New York, but there are many others, and their reputations vary.

What does the certificate say?  Minimally, you can get a verbal or written gem id.  That’s useful if there’s a dispute about whether or not the gem is real, or when there’s a mixup of parcels.  A full lab report will also provides you with the gem’s origin, treatments/enhancements, comments on clarity and color grade, aside from the standard stuff (weight, cut, color, dimensions).

What does the certificate not say? A certificate does not provide you with the appraisal value of the gem.  Determining value depends a lot on the current market and on the purpose of the appraisal (an appraisal for insurance purposes is usually done at full retail value, a wholesale appraisal or an appraisal for an estate sale is much lower). 

What does it cost? A full GIA report costs over $200.  Minimally, if you want just a verbal gem id from a smaller lab, that’s $20, and GIA does not offer it as far as I know.  I only went to GEMLAB once, and they did it for me for $20. 

How about appraising an entire parcel?  That’s done by sampling.  So it doesn’t cost more.

Are gem certificates standard when you buy gems?  With larger diamonds, they’re fairly common, but with colored stones, no.  They are rare, in fact.  I’ve only ever seen them for gems that cost several thousand dollars. And even then, most gems don’t have certificates.

Are gem certificates 100% reliable?  No.  They are only as good as the expertise of the certifier.  Every week, someone asks my gemstone dealer, D. for a second opinion on a gem and lab report.  D. only uses only a gem microscope, he does not do refractive index tests or use other machinery, but when it comes to rubies, emeralds, and sapphires, from what I have observed, his opinion is more trusted than that of some of the labs.  And does he challenge what the report says?  On occasion, yes. 

Do gem reports affect the price of the gem?  You bet.  And not just by the cost of the report.  It can easily add another $1000 to the price of the gem because of credibility alone.

What about the certificates that are offered by online gemstone sellers?  I’ve never asked for one, but this is what I think: if the report or the website doesn’t identify the lab that’s used, then it’s just the seller printing you a guarantee.  But you don’t need that, because you can usually return any gem that you bought on the internet (you should double check that of course), and the seller is not supposed to lie anyway (a direct lie is illegal, don’t forget that, and the internet is public).  So what does the report give you that you don’t already have in the online gemstone listing?

How can you really be sure that your gem is real, untreated, or what have you?  After a year and a half in the diamond district, this is what I’ve learned: not all gemstone dealers are gemstone experts.  Many are knowledgeable, but others are just in for a quick buck, moving a parcel or a single gem from one dealer to another.  And they don’t know diddly.  Also, not all dealers know if and how their gems are treated.  But when you ask directly you will get the best answer they can offer because otherwise they will lose their reputation.  A gemstone dealer that cheated you on purpose may never sell on the street again if this becomes public knowledge.  In short, all he or she has is reputation, and you have the power to destroy it.  Other than that, you have to get to know your sources.  Choose a few trustworthy ones for the gems that are difficult and expensive.  For some of the cheaper stuff, or the stuff that’s easy to id and isn’t usually treated, you can, to a degree, take your chances.  For the expensive stuff, you have to assume that the gem is at least heat treated or oiled (in the case of emerald).  Very few dealers will guarantee that a gem 100% untreated. 

The anecdote that led me to write this entry.  On my way home the other day, I cut through the local mall and happened by a large jewelry chain that had a special sale.  They had an independent gemstone and diamond dealer there with lots of gems, mountings, and a professional setter who would work on the spot.  So you could pick your gem and have it set right away.  I stopped to look at the colored stone section  There were several sapphires, all neatly packaged with weights and sizes listed, as well as the price tags: $2000 and up for 1 carat gems.  I pointed at a purple sapphire listed at around $2000 (an oval of approximately 1 carat) and asked about the origin.  “We’re not given the origins,” the rep said.  Well I thought that was just ridiculous.  I left, but not without pointing out to the guy that origin greatly affects price.  For example, a 1 carat heated purple Tanzanian sapphire might sell for $100 on the street.  A 1 carat purple Ceylon of the right saturation might sell for $500 or more.  A x5 markup is expected for retail, because everyone has to get paid (the rep, the guy the rep bought from, the jewelry store, and everyone who works there).  A x5 might in fact just cover those costs, to be fair.  But x20 would be totally unacceptable, even at a retail outlet in the mall. 

So what do you get from a reputable jewelry store chain that you don’t get from a small time, reasonably knowledgeable gem dealer on 47th?  Apparently, nothing.


Approximately 1 Carat Burmese Ruby, Unheated (and untreated), No Certificate

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