AGS vs GIA color grades

[reiddar]

After reading an article on this site about the different labs, it seems to be that AGS might be softer on grading color.

Anyone have any insight into this?

It would be interesting to see a larger sample done...say a 100 stones.

 

[WinkHPD]

After reading an article on this site about the different labs, it seems to be that AGS might be softer on grading color.

Anyone have any insight into this?

It would be interesting to see a larger sample done...say a 100 stones.

My personal experience is that they are very comparable to GIA in color and a bit stricter in clarity.

I have heard others say differently, but that has NOT been my personal experience.

Wink

 

[Claw M.D.]

I am by no means an expert, but for what it is worth (probably not much) I recently took 2 AGS certified H-color stones to an appraiser who says he grades "according to GIA standards". Both times he said the color of my stone was lower than his H comp stone (which he showed me - and my stones were definitely lower than his comp). For the second time, though, he broke out a new GIA certified I-color comp stone, and my H stone was better than the I comp. So, it could be that his H comp stone was a very good H (or had been mislabeled as an H), or that both of my stones were low Hs or high Is.

 

[WinkHPD]

I am by no means an expert, but for what it is worth (probably not much) I recently took 2 AGS certified H-color stones to an appraiser who says he grades "according to GIA standards". Both times he said the color of my stone was lower than his H comp stone (which he showed me - and my stones were definitely lower than his comp). For the second time, though, he broke out a new GIA certified I-color comp stone, and my H stone was better than the I comp. So, it could be that his H comp stone was a very good H (or had been mislabeled as an H), or that both of my stones were low Hs or high Is.

Or even that his master stones needed to be cleaned. Over time the girdle can pick up color from the tweezers used to hold them and they do need to be cleaned, boiled in acid, at least once per year.

Wink

 

[yssie]

I am by no means an expert, but for what it is worth (probably not much) I recently took 2 AGS certified H-color stones to an appraiser who says he grades "according to GIA standards". Both times he said the color of my stone was lower than his H comp stone (which he showed me - and my stones were definitely lower than his comp). For the second time, though, he broke out a new GIA certified I-color comp stone, and my H stone was better than the I comp. So, it could be that his H comp stone was a very good H (or had been mislabeled as an H), or that both of my stones were low Hs or high Is.

Or even that his master stones needed to be cleaned. Over time the girdle can pick up color from the tweezers used to hold them and they do need to be cleaned, boiled in acid, at least once per year.

Wink

Wink I have a quick question about this, if I may - do GIA, AGS, EGL, HRD,... use the same master stones? And do the manufacturers who supply to those labs make those master sets in different sizes - half-carat, 1ct, 2ct, etc. - thereby removing at least some of the guesswork on the part of the grader re. appropriate increase in saturation as size increases?

Also I believe I read on here that master stones are the "lowest/most tinted" that a stone of a particular grade ought to be, is this in fact the case?

Thanks!

 

[aquanaut]

I am by no means an expert, but for what it is worth (probably not much) I recently took 2 AGS certified H-color stones to an appraiser who says he grades "according to GIA standards". Both times he said the color of my stone was lower than his H comp stone (which he showed me - and my stones were definitely lower than his comp). For the second time, though, he broke out a new GIA certified I-color comp stone, and my H stone was better than the I comp. So, it could be that his H comp stone was a very good H (or had been mislabeled as an H), or that both of my stones were low Hs or high Is.

I have had the same exact experience with Mark from ERD.
He showed me an AGS H color stone that I was serisouly considering but I wanted to send it in to GIA to cross check before buying. After studying the stone in great detail, and showing it to some of his friends who work for the GIA Mark told me he did not think it would make a GIA H and hence I decided to pass on the stone to avoid potentially losing on the GIA report fee.

Later on when I spoke to another reputable vendor recommended here on price scope he seemed to imply that more often than not AGS H color is more like GIA I.
PLEASE DONT TAKE THIS AS FACT!
This is only what I have heard and experienced 1 time.

Would love to hear the experts chime in!

 

[WinkHPD]

I am by no means an expert, but for what it is worth (probably not much) I recently took 2 AGS certified H-color stones to an appraiser who says he grades "according to GIA standards". Both times he said the color of my stone was lower than his H comp stone (which he showed me - and my stones were definitely lower than his comp). For the second time, though, he broke out a new GIA certified I-color comp stone, and my H stone was better than the I comp. So, it could be that his H comp stone was a very good H (or had been mislabeled as an H), or that both of my stones were low Hs or high Is.

Or even that his master stones needed to be cleaned. Over time the girdle can pick up color from the tweezers used to hold them and they do need to be cleaned, boiled in acid, at least once per year.

Wink

Wink I have a quick question about this, if I may - do GIA, AGS, EGL, HRD,... use the same master stones? And do the manufacturers who supply to those labs make those master sets in different sizes - half-carat, 1ct, 2ct, etc. - thereby removing at least some of the guesswork on the part of the grader re. appropriate increase in saturation as size increases?

Also I believe I read on here that master stones are the "lowest/most tinted" that a stone of a particular grade ought to be, is this in fact the case?

Thanks!

Neil Beaty is probably a better person to answer this as to modern day practices, as I know they have changed since I graduated GIA in 1975 and bought my first master grading set of diamonds. I will answer to the best of my ability though and hope that Neil will show up later and correct any misstatements that I might make unintentionally.

I believe that current master sets may not have more than one or two split-grade stone i.e. F-G or H-I although my set of five stones has an E, an F-G, an H-I, a J-K and an L all in the .40 to .44ct range. I had to buy the stones and submit them both to AGS and GIA to have a set that was usable in both systems which were not so synonymous as they are today. There is no rule that the stones be at the bottom of each grade, as this would make it nearly impossible to assemble a set of stones. My split grade stones have the advantage of being at the bottom of one grade and at the top of the next, so that if a stone is ever so slightly better, it is the higher grade and ever so slightly worse, it is the lower grade. Personally I think this is MUCH better than trying to guess with a three stone set which of the grades between one stone and the next the color should be.

Assembling a master set today can be quite expensive, depending on the size of the stones you wish to use. I know of some houses that specialize in assembling these sets for jewelers, such as Gary W. Write Company in Arizona. There are some complicated rules about cutting and girdles and the price of tea in China that you have to adhere to in submitting for a set today, and although you can do it yourself, it may be a LOT easier to let someone do it for you.

It would be nice to be able to afford a one carat master stone set of for to five stones, but I do not know many jewelers who can afford to tie up that much money in master sets. It is my understanding that both GIA and AGS do have larger sets available, although I reserve the right to be wrong about that.

I have no idea what EGL uses for master sets, for all I can tell from their paper, egl Israel just makes up a grade that has no correlation to reality, so I hope that they have not wasted a lot of money on a set they are not using. It is sad to see how much that the poor quality of the paper from EGL Israel downgrades the perception of EGL in this country, as John Pollard assures me that they have a stellar reputation in China. EGL China is one of the highest respected Labs in China according to John who has been there two or three times as a speaker to the diamond industry there.

Wink

 

[denverappraiser]

GIA grades stones as 'color masters ' and this is a completely different service from their usual grading. AGS used to do the same but they dropped out of that business a few years ago. I think HRD does it as well but I'm not certain of this. The rules are slightly different from the standard ones in that they will grade split grades, they will reject stones with fluorescence, there are limits to the size variations within a particular set, they have no clarity grade but must not have visible inclusions from the pavilion side, etc. It's actually fairly difficult to build a set.

Most graders will have a set of anywhere from 3 - 15 stones in their master set and they will all be within 0.10cts of each other. It's fairly common to be in the range of 0.45, 0.80 and 0.90cts for the simple reason that this can turn out to be a fairly expensive 'tool'. I've got a 9 stone set of 0.43-0.53cts and I've got many thousands of dollars tied up in it. Lots of appraisers use CZ masters for this reason although I find that CZ's just don't look enough like diamonds for this to work and it's the rules for both AGS and AGA members that you use real diamonds to comply with their 'certified' gem lab status. Bumping up the size to 0.90-1.00 would increase the cost many fold.

As Wink points out, it's possible to change the color of the stones over time with the general grunge accumulated in using them. The metal from the tweezers getting into the tiny spaces on the girdle is especially incidious and it's important to be careful to keep them squeeky clean using some aggressive cleaning techniques or your grades tend to 'drift' downward. If you're not sure, ask your grader what they are using for color masters, what they use for color lighting, and how they keep things current (light bulbs change over time as well and need to be replaced well before they burn out).

I think it's IGI China that John has spoken of. As far as I know, EGL isn't there (yet). Other than the shared acronym and a history of animosity, EGL-USA and EGL-International are completely unrelated companies.

 

[WinkHPD]

GIA grades stones as 'color masters ' and this is a completely different service from their usual grading. AGS used to do the same but they dropped out of that business a few years ago. I think HRD does it as well but I'm not certain of this. The rules are slightly different from the standard ones in that they will grade split grades, they will reject stones with fluorescence, there are limits to the size variations within a particular set, they have no clarity grade but must not have visible inclusions from the pavilion side, etc. It's actually fairly difficult to build a set.

Most graders will have a set of anywhere from 3 - 15 stones in their master set and they will all be within 0.10cts of each other. It's fairly common to be in the range of 0.45, 0.80 and 0.90cts for the simple reason that this can turn out to be a fairly expensive 'tool'. I've got a 9 stone set of 0.43-0.53cts and I've got many thousands of dollars tied up in it. Lots of appraisers use CZ masters for this reason although I find that CZ's just don't look enough like diamonds for this to work and it's the rules for both AGS and AGA members that you use real diamonds to comply with their 'certified' gem lab status. Bumping up the size to 0.90-1.00 would increase the cost many fold.

As Wink points out, it's possible to change the color of the stones over time with the general grunge accumulated in using them. The metal from the tweezers getting into the tiny spaces on the girdle is especially incidious and it's important to be careful to keep them squeeky clean using some aggressive cleaning techniques or your grades tend to 'drift' downward. If you're not sure, ask your grader what they are using for color masters, what they use for color lighting, and how they keep things current (light bulbs change over time as well and need to be replaced well before they burn out).

I think it's IGI China that John has spoken of. As far as I know, EGL isn't there (yet). Other than the shared acronym and a history of animosity, EGL-USA and EGL-International are completely unrelated companies.

AAAck! I think you are right. No, I now you are right. Thank you for reminding me of which labe he speaks. LOL, he gets so mad at me when I speak poorly of IGI and I keep telling him when IGI US quits doing dufus things like quadruple markup prices on their diamond papers to make it easy to dupe unsuspecting retail clients that I might begin to take them serious in this country.

Wink

 

[yssie]

Thank you for the thorough - and interesting! - responses, Wink & Neil.

I had wondered about this - it seemed like an awfully expensive proposition to accumulate sets of 1 caraters! Unless you start using CZs, I guess.. but I assumed there was some universal supplier for them, and some process to get them that all jewellers just knew to navigate - it sounds like you have to find your own stones, or pay someone to put them together for you.

Neil, or Wink, since I believe you've both been in the business for some time can I ask if you've noticed any - what's the word - trends, I guess? Do the grading stones you acquired a decade ago still hold true and relevant to modern grading, and have they throughout that time, do you feel? Do jewellers often 'inherit' these master sets - so, potentially spanning multiple decades?

 

[kenny]

Good question Yssie.

Is a 1955 GIA G the same as a 2011 GIA G?

Or has there been pressure or a tendency for grades to get more (or less) generous over a long period of time?

 

[denverappraiser]

Well, I can’t speak for Wink but 1955 is a few years before my time. That said, no I don’t think there’s been much change other than some variations on how they handle fluorescence in the stone and/or the environment (which can be a big deal by the way).

I talk to appraisers fairly often and, frankly, I’m not too sympathetic of the complaints that a set of masters is too expensive as an excuse for buying CZ's. It’s just part of the cost of being a professional, and if you don’t want to be a professional then you should go get a real job. It’s not like they’re perishable and when you finally get tired of the trade you can sell them off to some kid who wants to grow up to be an appraiser just like you. There are a LOT of wannabe's in this business. If anything it’s a decent investment since it’s not going to be any easier for them than it was for you. It’s a significant competitive advantage to be one of the few people in a particular market who is properly equipped and if you’re going to lay out the kind of money required to get the proper training, it only makes sense to buy the tools that go along with it. For appraisers who are a little light on the experience it's even more important. At least you can BUY masters. Experience can only be gained by putting in the time, and maybe not even then.

 

[WinkHPD]

Well, I can’t speak for Wink but 1955 is a few years before my time. That said, no I don’t think there’s been much change other than some variations on how they handle fluorescence in the stone and/or the environment (which can be a big deal by the way).

I talk to appraisers fairly often and, frankly, I’m not too sympathetic of the complaints that a set of masters is too expensive as an excuse for buying CZ's. It’s just part of the cost of being a professional, and if you don’t want to be a professional then you should go get a real job. It’s not like they’re perishable and when you finally get tired of the trade you can sell them off to some kid who wants to grow up to be an appraiser just like you. There are a LOT of wannabe's in this business. If anything it’s a decent investment since it’s not going to be any easier for them than it was for you. It’s a significant competitive advantage to be one of the few people in a particular market who is properly equipped and if you’re going to lay out the kind of money required to get the proper training, it only makes sense to buy the tools that go along with it. For appraisers who are a little light on the experience it's even more important. At least you can BUY masters. Experience can only be gained by putting in the time, and maybe not even then.

The above answer is one of the reasons I love sending people to Neil. He does not know the translation of "sugar coat" so what you get from him is the unvarnished truth, whether or not that was what you wanted.

However, in 1955 I was only 9 years old and although I was already buying costume jewelry from the local drug store display counter for my mom, it would be another 20 years in early November 1975 until I got my GG from GIA. That was just days before my son Wink III was born and I finished second in the class behind my wife, who was very irritated that I studied for a couple of hours as I was busy running my little business out of our apartment and running into downtown LA to the 607 building to buy and sell things while she studied all day every day for about a week whilst almost 9 months pregnant.

I think the biggest change since I got my first set in 1976 is the fact that it would cost many times the slightly less than $2,000 that I spent for my five stone set of .40 to .44ct stones. All of my stones are VS1's or better clarity wise, so you can imagine that the what was then considered ideal cut E-VS1 would cost more than I paid for the whole set today. (And that is before you pay for the GIA to bless them.)

Wink

 

[Jim Summa]

I bought my first 4 stones (masters) from a retiring jeweler around 1985, all around a 1/3 of a carat each. He was pretty good about the price, I think they ran about $850. I do wish they were a little bigger, but I do use them.

I still toss just about every diamond that comes thru here on they tray, just to see how they measure up and if I agree with what I am seeing....This is also the best way for people to get a feel for the ever so slight differences from one grade to the next.
I did surprise myself this past Saturday...I now have 5 masters because its a requirement by AGS (Should maybe require more than 5 but thats for another thread.)

The surprise is I was working the stones against an unknown 1 ct. and something didn't look right, I cleaned them and looked later and it still didn't look right.

So I picked out a stone...my I color master and looked at the girdle and it read GIA with a number and I darned near fainted!
I had sold a 1/3ct. GIA I color a week earlier and somehow mixed them up on the tray!
(I am trying to figure out what didn't look right, except I am dealing with diamonds.)

Another thing that was interesting is when I became a CG I had to send my 4 stones to the AGS lab to be certed as masters and lasered with numbers (good idea!)
When the stones came back, one of the stones, a "J" came back a "K".

Well, today the customer came in wearing my master diamond, she won't be forgetting this one anytime soon.

 

[Haven]

The surprise is I was working the stones against an unknown 1 ct. and something didn't look right, I cleaned them and looked later and it still didn't look right.

So I picked out a stone...my I color master and looked at the girdle and it read GIA with a number and I darned near fainted!
I had sold a 1/3ct. GIA I color a week earlier and somehow mixed them up on the tray!

How did you manage to do this?!?!

 

[Jim Summa]

I will have to get back to you on that one...

 

[yssie]

I bought my first 4 stones (masters) from a retiring jeweler around 1985, all around a 1/3 of a carat each. He was pretty good about the price, I think they ran about $850. I do wish they were a little bigger, but I do use them.

I still toss just about every diamond that comes thru here on they tray, just to see how they measure up and if I agree with what I am seeing....This is also the best way for people to get a feel for the ever so slight differences from one grade to the next.
I did surprise myself this past Saturday...I now have 5 masters because its a requirement by AGS (Should maybe require more than 5 but thats for another thread.)

The surprise is I was working the stones against an unknown 1 ct. and something didn't look right, I cleaned them and looked later and it still didn't look right.

So I picked out a stone...my I color master and looked at the girdle and it read GIA with a number and I darned near fainted!
I had sold a 1/3ct. GIA I color a week earlier and somehow mixed them up on the tray!
(I am trying to figure out what didn't look right, except I am dealing with diamonds.)

Another thing that was interesting is when I became a CG I had to send my 4 stones to the AGS lab to be certed as masters and lasered with numbers (good idea!)
When the stones came back, one of the stones, a "J" came back a "K".

Well, today the customer came in wearing my master diamond, she won't be forgetting this one anytime soon.

I'm laughing out loud

Neil - I have to say, I am shocked that the standards haven't changed or fluctuated. The natural way of things is to adapt - to one thing or another - so whatever is holding colour grading static must be truly a rock solid institution..!

 

[denverappraiser]

Yssie,

Diamonds, and diamond masters, don't depreciate. GIA is still using the same masters they did in 1955. When they open a new lab or a new workstation in the old lab, they use those very same masters to assemble the new set. The lights that people use have changed, and that does have an affect in how things are percieved and gives a bias towards some things and against others, but the masters themselves are really pretty constant as are the procedures used for certifying 'new' masters. Wink's stones are every bit the same as they were in 1973 (I'm assuming he is diligent about keeping them clean) and he bought them 'used'. I think I bought my first master in 1990 and I too bought it 'used' from a retiring gemologist. My very favorite master is an ACA that I bought from Whiteflash and submitted through the system in about 2004 or so. My most recent addition was in February 2011 by the way. I now have an S-T in the set. You wouldn't believe how hard that was to find.

 

[reiddar]

All that being said, if you had to buy a stone on paper, would you trust the color from a GIA cert. or AGS cert. more?

 

[marcy]

I really enjoyed reading this thread. Thanks to all of the experts for this information. I went from an AGS0 to GIA EX and keep wondering if I would have liked another AGS0 better - now I feel much better.

 

[denverappraiser]

All that being said, if you had to buy a stone on paper, would you trust the color from a GIA cert. or AGS cert. more?

I wouldn't buy a stone on paper.

If I were choosing what to look at based purely on paper and all things were otherwise equal I would choose AGS because I prefer their cut grading system. I find their grading on clarity and color to be very comparable.

Unfortunately, all things are rarely equal.

 

[marcy]

I would choose AGS because I prefer their cut grading system

.

That is what I was afraid of . . .

 

[yssie]

I would choose AGS because I prefer their cut grading system

.

That is what I was afraid of . . .

Why? Your stone is your stone regardless of who grades it, if anyone!

AGS does not have a monopoly on well-cut stones, they just give you more info on any stone that they get their hands on, and because the real value of an AGS report is in the premium that an AGS0 commands, manufacturers who cater specifically to a cut-nut niche market are naturally going to tend to send stones that are likely to warrant the 0 grade - and thus the premium - to AGS, to make them even more attractive to a consumer base that is largely looking for that very specific product - and to shy from sending or perhaps even stocking stones they feel would not. So that says something about how those boutiques operate, but there are plenty of vendors who send perfectly lovely stones to GIA

 

[Paul-Antwerp]

You are right, Yssie, in the sense that a lab is only a reporter, but has no direct influence on the quality of a diamond.

We have, aside from our own brand, also unbranded production of the same quality for other retailers, and they often prefer to use GIA as a lab. As such, this also gives me a general idea about the small differences in grading between the labs.

In general, they are on par, but that does not mean that they will grade exactly the same. My feeling and experience are roughly the following:
- In colour, GIA is a tad stricter than AGS, I estimate about one tenth of a grade.
- In clarity, it is the other way around and the difference a bit higher, I would say AGS about three tenths of a grade stricter.
- In comparison, HRD, I regard them about two tenths of a grade stricter in colour than GIA, but about half a grade less strict in clarity.

A consumer thus would like to have the colour graded by HRD and the clarity by AGS, and a seller would probably prefer the colour graded by AGS and the clarity by HRD. However, both are combined on one report, so that does not work.

If we look value-wise, comparing GIA to AGS, the slightly stricter clarity has more effect than the colour, so the total AGS-grade on colour and clarity would be a bit more valuable. This also reflects in the small premiums for AGS-reports compared to GIA.

Live long,

 

[yssie]

In general, they are on par, but that does not mean that they will grade exactly the same. My feeling and experience are roughly the following:
- In colour, GIA is a tad stricter than AGS, I estimate about one tenth of a grade.
- In clarity, it is the other way around and the difference a bit higher, I would say AGS about three tenths of a grade stricter.
- In comparison, HRD, I regard them about two tenths of a grade stricter in colour than GIA, but about half a grade less strict in clarity.

A consumer thus would like to have the colour graded by HRD and the clarity by AGS, and a seller would probably prefer the colour graded by AGS and the clarity by HRD. However, both are combined on one report, so that does not work.

If we look value-wise, comparing GIA to AGS, the slightly stricter clarity has more effect than the colour, so the total AGS-grade on colour and clarity would be a bit more valuable. This also reflects in the small premiums for AGS-reports compared to GIA.

Live long,

Interesting observations on the differences Paul, thanks for sharing them.

 

[Paul-Antwerp]

And I should add, Yssie, that this differs even when we are talking different colours and different clarities.

Live long,

 

[marcy]

Thank you for more thoughts and observations, Paul. They are very interesting.

Yssie, my GIA EX is a very nice stone but I was unable to compare it to an AGS0 of similar carat weight when I bought it. The stone I traded in was an AGS0 but they didn't have any AGS0 diamonds in the colorless 3/4 range. We compared quite a few GIA EX and picked the one we both thought performed the best (and did use the cut advisor to help). I just sometimes wonder if my old AGS0 had a better cut than my current GIA EX. I know it's an impossible comparison because they are different sizes and mounted in different settings and I probably just worry too much.

Funny thing about this discussion though - my AGS 1/2 ct was an E and my GIA 3/4 ct is a F but I swear it looks whiter.

ETA: And of course you can find stunning diamonds that don't have a certificate at all.

 

[marcy]

Yssie, thank you. My response made me think of something and I now I am completely over my GIA vs AGS worries. The day we were getting my upgrade we did put my GIA in my old setting and both of us immediately said "we can't tell the difference". It looked like the exact same ring even though the center diamond was .28 ct more.

 

[kal2021]

Paul, you mentioned many retailers prefer GIA - do you know why that is? I have never been able to find a B&M store that carried AGS graded stones, and I've always wondered why!

 

[Paul-Antwerp]

Hi Kal,

I had to look back to see in what context I actually mentioned that many retailers prefer GIA. There are many reasons:

The most important reason probably is that GIA, unlike AGS, has succeeded in becoming a household-name with the public. There simply is much more brand-recognition of the 'brand' GIA, which makes the selling-and-presentation-process for any retailer easier. Throughout the years, this position has been strengthened by jewelers themselves, who most often use GIA as the benchmark when introducing another lab. This is one of the aspects that I often criticize AGS about, when we are meeting with representatives.

Also, because of that, there is a larger availability of GIA-graded diamonds from a bigger pool of cutters. Working with GIA-graded diamonds gives the retailer more liberty and a higher chance of finding diamonds for every request that comes in. The latter factor might well become more important in the next years.

On top of that, and now only are we touching my comment which was the specific case of retailers who can choose themselves which lab is used for their 'store-brand', there is the factor of price-value. For some retailers, this may be a calculated decision while some just make it intuitively. The small difference in grading-trend between AGS and GIA has an impact on value. AGS' slightly softer grading of colour (I estimate one tenth of a grade) slightly reduces the value of the AGS-report, but the opposite, GIA's a bit more than slightly softer grading of clarity (I estimate three tenths of a grade) has a much higher opposite effect. As a result, trend-wise, AGS-paper has more value than GIA.

But with them being less known by consumers, which makes selling them harder, definitely harder to even overcome a price-premium, it is clear that choosing for GIA brings in more dollars faster for that retailer than choosing for AGS.

The last part of the reason is difficult to explain, so let me try to give this example. Imagine a consumer on PS asking about three GIA-graded stones, all G-SI1, and one AGS-graded stone, also G-SI1. The AGS-stone is about 4% more expensive, and there is a small chance (1 out of 10) that it is a GIA-H. On the other hand, with a chance of 1 out of 3, one of the GIA-stones is surely a AGS-SI2. Without any other observable differences, there is a high chance of a GIA-stone being chosen, and nobody will know if it is the SI2. In any case, the retailer won by using GIA as a lab, and when the actual SI2 is sold, he is winning big time.

In that sense, it is well advised to work with a trusted professional. I must add, do not mistake this with the term gemologist, being gemologist is the first step to become a professional, afterwards you have to earn trust.

Live long,