Master stones color grading set advice

[DonaldsonsJewelers]

For years in my family's jewelry business we graded color of diamonds with a five diamond Master Stone set and my father and grandfather have both passed and I am no longer doing appraisals and I'm looking to find information concerning this master set. I have searched high and low not able to find the certification information for this set that was put together in the mid-70s and I'm not able to determine whether it was certified by Gia or AGS and thought someone might recognize the set and possibly give me some more information concerning it. It's been years but I was a RJ with AGS and a GG & GJ graduating from GIA Santa Monica campus. Also member of KJA but it has been 2 decades since I participated in these organizations. Thanks for any information you can provide.

 

[DonaldsonsJewelers]

I'm thinking most likely AGS due to the numerical color grading designation.

For years in my family's jewelry business we graded color of diamonds with a five diamond Master Stone set and my father and grandfather have both passed and I am no longer doing appraisals and I'm looking to find information concerning this master set. I have searched high and low not able to find the certification information for this set that was put together in the mid-70s and I'm not able to determine whether it was certified by Gia or AGS, most likely AGS due to the numerical grading designation and thought someone might recognize the set and possibly give me some more information concerning it. It's been years but I was a RJ with AGS and a GG & GJ graduating from GIA Santa Monica campus. Also member of KJA but it has been 2 decades since I participated in these organizations. Thanks for any information you can provide.

 

[MissGotRocks]

@oldminer, any ideas?

 

[MissGotRocks]

I'm thinking most likely AGS due to the numerical color grading designation.

Why were only five stones used as there are more color grades than that? Did you just estimate the colors that correlate to the missing numbers? Did you grade the diamonds face up unlike what today’s labs do? Fascinating - would love to hear all about this!

 

[DonaldsonsJewelers]

Why were only five stones used as there are more color grades than that? Did you just estimate the colors that correlate to the missing numbers? Did you grade the diamonds face up unlike what today’s labs do? Fascinating - would love to hear all about this!

Don't have an answer for that they were just what we used to grade color when we use the AGS system. And then we had a conversion chart to compare it to Gia grade when we partially switch to that system in the '80s

 

[MissGotRocks]

It is probably just the picture, but there doesn't seem to be a lot of color variation in the samples. Did you compare diamonds face up to the samples or did you compare them face down?

 

[DonaldsonsJewelers]

Not using any samples and the tray that they're in is non-florescence and they are to be graded upside down with the viewing angled established by the tray that they sit in but I will take a photo so you can see the color differentiation as much as possible via a photo

 

[Karl_K]

kewl... thanks for posting these.
I am going to ping a few more people for you.
@Garry H (Cut Nut) @Wink @denverappraiser

 

[headlight]

Why were only five stones used as there are more color grades than that? Did you just estimate the colors that correlate to the missing numbers? Did you grade the diamonds face up unlike what today’s labs do? Fascinating - would love to hear all about this!

This is actually similar to how they teach color grading at GIA… they don’t have every color for a master set. The way the grading process works doesn’t require every color. You just have to have enough masters to have the reference points to get you to the right place in the lineup to make the color call. It’s actually very interesting and that was one of my favorite parts of that lab course.

 

[MissGotRocks]

This is actually similar to how they teach color grading at GIA… they don’t have every color for a master set. The way the grading process works doesn’t require every color. You just have to have enough masters to have the reference points to get you to the right place in the lineup to make the color call. It’s actually very interesting and that was one of my favorite parts of that lab course.

I am sure that the differences in color can be small, but this could also account for the color grade differences. While it has always been up to human eyes to determine, you would think that having all of the colors would be beneficial. The saving grace I suppose is that more than one person grades, so it is a collaboration.

 

[headlight]

I am sure that the differences in color can be small, but this could also account for the color grade differences. While it has always been up to human eyes to determine, you would think that having all of the colors would be beneficial. The saving grace I suppose is that more than one person grades, so it is a collaboration.

The human element is definitely a factor, but you have to remember that at a reputable geological laboratory as GIA is, graders have seen an incredible number of stones and have very experienced eyes. They also only grade for a specific time period at one sitting. But with regard to the idea of having a master stone for every color grade, even that would not be sufficient because each grade is not a hard and fast designation… within each grade is a range, hence why we hear sometimes that a stone was described by a SA as a high G or a low H, etc. I find it all really interesting.

 

[MissGotRocks]

The human element is definitely a factor, but you have to remember that at a reputable geological laboratory as GIA is, graders have seen an incredible number of stones and have very experienced eyes. They also only grade for a specific time period at one sitting. But with regard to the idea of having a master stone for every color grade, even that would not be sufficient because each grade is not a hard and fast designation… within each grade is a range, hence why we hear sometimes that a stone was described by a SA as a high G or a low H, etc. I find it all really interesting.

It is very interesting!!

 

[headlight]

It is very interesting!!

I know you would be an amazing Graduate Gemologist!

 

[MissGotRocks]

I know you would be an amazing Graduate Gemologist!

Thanks - do you use your professionally?

 

[oldminer]

The numerical grading corresponds to GIA grades and is likely a set made of an AGS store/member years ago. There were papers provided at the time, diamond papers actually, with printed labels with the AGS grade and the GIA equivalent on them. The stones you have look like 1/4 to 1/3 ct each and if they are the original stones, it may be a useful tool that is difficult to come by today. The GIA has altered their color grading in subtle ways since the 1970's, but still, such sets becoming available are scarce. AGS 'might" have a record of the "set number" in their old paper files. That would probably lead to their copy of the paperwork and give you the authentication possibility to sell the set for close to Rap prices to a dealer or an appraiser. It would be a good idea to call AGS and ask if they might be helpful.

Although I doubt it, look on the girdles to see if they were laser inscribed. I think most were made before that technology, but they may have been done later.

If the holding tray lifts out of the box, maybe a piece of the original paperwork is under it. That would be a nice piece of luck.

If any of these diamonds show more than slight fluorescence, they may not be the original stones, since fluorescence disqualifies them as part of a master set. Inadvertent switches with other diamonds happen by accident sometimes.

I hope this proves helpful.

 

[oldminer]

Added note:
Keppie and Lazare Kaplan diamonds made many of these sets for AGS members. Kaplan is still in business and might have a record? Keppie is closed, so that's not likely.

 

[headlight]

Thanks - do you use your professionally?

I do not use my G.G. professionally. I would love to find some work (could be anything) for a local jeweler on a part-time, flexible basis but that’s not easy to find. I did it as a life-long learning venture and not with a career intention but it would still be great to be around it. I do GIA continuing ed to keep myself in it.

 

[0-0-0]

@oldminer Why is there a jump from 3 to 5?

 

[oldminer]

There is certainly an AGS color 4, but this set contains what should be a 1 2 3 5 and 6 color. Here is an entire scale of equivalents.

 

[Texas Leaguer]

I suspect @oldminer is correct- it's a third party set put together for AGS members. I would start with a call to AGS. I would also call GIA as the stones would have been graded by them and they may be able to provide helpful info.

GIA has specific requirements for jewelers or vendors submitting stones for the purpose of making master grading sets.

 

[Wink]

This is my response to the question by @MissGotRocks about why only five diamonds in the master set. Those sets were expensive to put together, and many people made dow with sets of only three or four. My color set was with five forty pointers, I had an E-F split grade, a G, an H-I, a J-K and an L. It made color grading relatively easy. You put the stone to be graded in a slotted tray on its side, and put a color grading stone on one side of it until you are close. I found the split grades to be very helpful, especially in the higher colors. If a stone was the tiniest better than my E-F I knew it to be at least an E. If it was even the tiniest bit lower, then I knew it to be an F. I found it very important to put the grading stone on both sides of the stone being graded. I always did so and there were some diamonds that looked better when they were observed to the left of the color master and others looked better when to the right of the color master.

I can say the age of the grader is important and the ability to properly grade color deteriorates with age. If you are above the age of 50, I will doubt your ability to do what you once did at the age of twenty to twenty- five. At 77, I will no longer will do a color grade of a diamond for an appraisal. Of course, I am retired, so I do not do appraisals anymore anyway.

 

[MissGotRocks]

This is my response to the question by @MissGotRocks about why only five diamonds in the master set. Those sets were expensive to put together, and many people made dow with sets of only three or four. My color set was with five forty pointers, I had an E-F split grade, a G, an H-I, a J-K and an L. It made color grading relatively easy. You put the stone to be graded in a slotted tray on its side, and put a color grading stone on one side of it until you are close. I found the split grades to be very helpful, especially in the higher colors. If a stone was the tiniest better than my E-F I knew it to be at least an E. If it was even the tiniest bit lower, then I knew it to be an F. I found it very important to put the grading stone on both sides of the stone being graded. I always did so and there were some diamonds that looked better when they were observed to the left of the color master and others looked better when to the right of the color master.

I can say the age of the grader is important and the ability to properly grade color deteriorates with age. If you are above the age of 50, I will doubt your ability to do what you once did at the age of twenty to twenty- five. At 77, I will no longer will do a color grade of a diamond for an appraisal. Of course, I am retired, so I do not do appraisals anymore anyway.

Thanks for your detailed explanation Wink! I know that you have had a lot of experience with this sort of thing and I value your input. I find this all very interesting!