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Calling the pricescope experts RE: HCA, recutting.

C

ccmans

Rough_Rock
Joined
May 30, 2017
Messages
21
Hello!

I was surprised when I recently saw that the GIA Ex stone I own is rated 5.5 on the HCA. When I bought it I had no idea about the HCA or any of this stuff, just that I should only buy GIA Ex or AGS0. I thought the stone looked nice (and still do!), but alas it is not for me, it's for her. My question is: if she doesn't find it brilliant enough, would it be possible to recut just the pavilion angle? Here are the specs.

1.2 ct
SI1
Table 60
Depth 61.3
Crown 33.5
Pavilion 41.6
Lower half 80%
Star 55%
4% girdle

I tried the HCA with 41 as the pavilion angle and it came up to a 1.9. I know there are risks to recutting a stone, but in your expert opinions is it worth looking into have the pavilion angle reduced? Or is there really no guarantee that a reduction like that would really help?

Thanks for your opinions! If she's happy with it I'm happy (haven't given it to her yet), but I'm just checking what my options are if she doesn't like it!

Unfortunately I dont think returning it is possible!
 
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Ditto Kenny...shoot BGD an email with your question. The inclusions (SI1) would also have to be evaluated to make sure its re-cut-able. Some are not
due to the location of the inclusions. You might send a copy of your cert with the email.

Does whomever you bought it from have a good trade up policy? If they do, that may be the better way to go.
 
HI ccmans!
Keep in mind that there's different "flavors" of super well cut Round Brilliant stones.
It's entirely possible she ( and you) may prefer the stone you have to a stone with a lower HCA score.
Best course of action would be if you can see some diamonds with lower HCA scores and compare- before spending money and or taking actions on a stone which can't be undone.
 
Thank you for the replies!

Kenny and tyty I appreciate the suggestion. I sent a feeler email to Brian Gavin to see what his thoughts on the stone are!

Rockdiamond, I feel this is sound advice. I wouldn't be sending it anywhere until she sees it. After all, I want this to be the perfect stone for her. Maybe this is her definition of perfect. My eyes are not trained for identifying diamond nuances, but I've read a lot of reviews saying that >4 HCA stones are considered pretty bad. Maybe I need to see it against a really ideal diamond to see the difference clearly.
 
What does the ASET image look like? I think that would be my next step.

There literally are lots of great looking diamonds that are not cut to today's modern H&A superideal proportions. There might be nothing wrong with that if you have a good performer and you like the look of it. I had an old diamond with wonky symmetry recut and I really don't think it gained much other than better symmetry and some well-defined arrows. It lost diameter. There was nothing wrong with the recut that Brian Gavin did. But in retrospect, I think the recut changed the appearance of the diamond and reduced its face-up size but performance was above-average either way. Sometimes they have to take off a lot of material to hit the ultimate performance + H&A superideal symmetry, and maybe some diamonds are good enough left as-is.
 
Good point AdaBeta. This really would be a last resort pending her opinion of the stone. You'll have to pardon my ignorance, but are ASET images those red light diagrams I see of diamonds on this site? How do I go about getting one, is there a calculator like HCA?
 
The images with only red are not ASET. https://ideal-scope.com/using-aset-scopes/
They are Idealscope. https://www.pricescope.com/tools/ideal-scope

ASET will have 3 colors, red, green and blue.
Over the years the pros I respect here state for rounds all you need is the red Idealscope image
ASET is the tool to use the evaluate the cut of all the other shapes.

HCA is a math thing that crunches numbers.
The scopes are optical devices that use light they have colored to reveal cut info.
 
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Ahh I see, thanks Kenny. I'll check some local jewellers and see if they have one on hand.
 
ccmans said:
Ahh I see, thanks Kenny. I'll check some local jewellers and see if they have one on hand.
Click to expand...

It would be fairly rare to find a jeweler with an ASET or Idealscope, because most don't exclusively carry top cut stones. So they don't want tools that will show the more poorly cut ones!

You are showing her the stone before it is set or you propose? Because someone just looking at a random diamond with no prior knowledge of diamond cut will have no idea whether it is a good one or not.

Will your jeweler let you exchange it? We could at least help you with the parameters of getting a stone that is more likely a well performing one.
 
diamondseeker2006 said:
It would be fairly rare to find a jeweler with an ASET or Idealscope, because most don't exclusively carry top cut stones. So they don't want tools that will show the more poorly cut ones!

You are showing her the stone before it is set or you propose? Because someone just looking at a random diamond with no prior knowledge of diamond cut will have no idea whether it is a good one or not.

Will your jeweler let you exchange it? We could at least help you with the parameters of getting a stone that is more likely a well performing one.
Click to expand...

Ahh I see, shame most places wont have the ASET tools.

I definitely wont be showing her the diamond before it is set or before the proposal. She is going to get the finished product, and she wanted it to be a surprise. I guess the bolded part works in my favour since she definitely doesn't know too much about diamonds! Bottom line, I just want her to love the ring.

Unfortunately I don't believe I can exchange it. I should be getting the full ring within a few weeks (custom design, it has been a process). Now that I am aware that it doesn't have a great HCA rating, I'll really scrutinize it and see if the "Fair/Good" rating really holds weight.
 
Just remember that HCA is a tool that helps rule out diamonds. She may find the diamond ring absolutely beautiful.
 
I think unless your jeweler would let you exchange it right now, you need to just let this go and never mention to her anything about these numbers, etc. She will be thrilled to get engaged with a beautiful ring, and I would not cause doubts in her mind about it after the fact.
 
Sounds like you may be on the hook for the setting because it is custom but not the stone. I think it would be unusual for a jeweler to make you continue to buy a stone if you're not happy
 
I would 100% try to exchange that stone! you don't even have the ring yet! Whatever the jeweler tried to tell you, don't give in! You may owe them for the setting but walk away from that diamond, please.
 
ccmans said:
Thank you for the replies!

Kenny and tyty I appreciate the suggestion. I sent a feeler email to Brian Gavin to see what his thoughts on the stone are!

Rockdiamond, I feel this is sound advice. I wouldn't be sending it anywhere until she sees it. After all, I want this to be the perfect stone for her. Maybe this is her definition of perfect. My eyes are not trained for identifying diamond nuances, but I've read a lot of reviews saying that >4 HCA stones are considered pretty bad. Maybe I need to see it against a really ideal diamond to see the difference clearly.
Click to expand...

When you look at a diamond to assess its performance, be sure to look at it in multiple lighting environments. If you look at and AGS graded ideal cut versus this GIA excellent, you will probably notice substantial improvement in brilliance and dispersion.

While I will agree with my friend Rockdiamond that it is possible that you and she will like a poorly cut diamond better than a well cut diamond, I can tell you with more than forty years of experience that it is highly unlikely.

Many bricks and mortar jewelers will tell you that color and clarity are the most important factors in a diamond's beauty, I will argue that Cut is KING! With poor cutting even a D-IF will look dull and boring. I know this having seen far too many lifeless lumps of crystallized carbon touted as valuable D-IF quality gems.

I advise looking at some well cut diamonds to let YOUR eyes tell you what YOU like. If you are comparing a truly well cut diamond to the diamond you have described to us, I think you will instantly see a huge difference, especially in lower light conditions away from the glare of jewelry store lights that are designed to make even glass sparkle.

Wink
 
Hi all
Wink- all due respect but where did I EVER suggest buying a poorly cut diamond?
I do have a basis in extensive real world experience with GIA "normal" triple x as well as AGS 0. "Super Ideals"
It's just plain wrong for anyone to suggest the op has a poorly cut stone sight unseen.
I'd also caution against trying to influence op based on what you feel Wink. Ive also got over 40'years experience. Many people STILL prefer 60/60.
Encouraging the op look in good lighting without pre conceived notions is the best help we can give.
 
Hi everyone, thank you for taking the time to reply in the thread.

I stopped by the jeweller and took a look at the diamond again. I checked it out in various different lighting (outdoors, indoors, dim lighting, spot lighting) and honestly it still looked beautiful to me. Without another stone to compare it against, I really can't determine if the cut really is that bad, but I have decided not to worry too much about it until she sees the ring; and if she says anything I'll revisit the re-cutting issue. The ring should be done soon so I'll make sure to post a photo of it when its completed!
 
Ccmans- best of luck!!
Rest easy. The chances of your GIA graded EX cut grade stone being "poorly cut" are minuscule.
In the "real world" your diamond has the same worth as a stone with the same GIA grade and a lower (better) HCA score unless we're comparing to a branded Super Ideal cut- which would likely cost more.
Here on PS there's many consumer participants that want a "Super Ideal" cut.
And it's also true that there's dealers posting here who are very dedicated to Super Ideal cuts. I don't blame them- super ideals are gorgeous. When a dealer is dedicated to their product it's admirable. But it's important to put dealers opinions in context ( even mine:). There's plenty of very well cut GIA Ex and even some VG stones that can also be amazing.
 
The simplest least weight loss is to cut the pavilion only to around 41.1 degrees.
This will drop the weight below 1.20ct which causes an economic loss of +5% because there is a small weight catagory jump at 1.20ct.
Weight loss doing pavilion only will be 0.01 to 0.02ct.
the stone would end up close to David's Rock n Roll 60:60
 
Thanks Garry!
Based on your calculations, we'd have about 5% reduction in value based solely on cutting loss of weight.
Then, of course, we have cutting fees, which will be fairly substantial considering we need an expert. Then a new AGSL report.
It's not going to be cheap.
Are you in agreement that if a person really wants an AGSL0 it's far simpler and smarter to simply buy such a stone as opposed to a recut?
This is apart from the issues of appearance. Based on the information provided, there's no way any of us can state that every single observer ( or even a wide margin) will agree that whatever might be done to the stone would be a visual improvement.
 
Personally I feel that the 60:60 preference highlighted above and 33.5/41.6 are very different. I thought my HCA 5.3 diamond score looked incredible in the store until I took it outside the store. Then I saw an HCA 1.3 and knew the difference immediately. My (now departed) grandma with her poor eyesight couldn't believe the difference.

Personally I'm not a fan of the larger table reflection of 41.6 pavilion, particularly combined with a 60 table. I think many assumptions can be accurately made from numbers alone, but no assumptions can be made on a persons perception. It is just as well that the OP and their significant other are diamond novices and can enjoy their diamond without preconceived perceptions on their preference
 
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... and do keep in mind that vendors who sell non-ideal cut diamonds have a financial incentive to poo poo cut tools that reject their inventory.
Follow the money, as they say.
 
kenny said:
... and do keep in mind that vendors who sell non-ideal cut diamonds have a financial incentive to poo poo cut tools that reject their inventory.
Follow the money, as they say.
Click to expand...
What if those vendors also are dealers of Super Ideals Kenny?
 
gm89uk said:
Personally I feel that the 60:60 preference highlighted above and 33.5/41.6 are very different. I thought my HCA 5.3 diamond score looked incredible in the store until I took it outside the store. Then I saw an HCA 1.3 and knew the difference immediately. My (now departed) grandma with her poor eyesight couldn't believe the difference.

Personally I'm not a fan of the larger table reflection of 41.6 pavilion, particularly combined with a 60 table. I think many assumptions can be accurately made from numbers alone, but no assumptions can be made on a persons perception. It is just as well that the OP and their significant other have diamond novices and can enjoy their diamond without preconceived perceptions on their preference
Click to expand...
hi gm89uk! I am extremely familiar with HCA, and I did "poo poo" it out of hand at first. Years ago.
Since then I've learned a lot.
The HCA is a remarkable invention and does a great job.
But it does not work in the manner you're implying.
It's a rejection tool for buying online, where you can't see the diamonds.
Stones that score low ( well) on HCA have a consistently nice look.
In terms of what it does reject, I still have issues.
Simply because a stone is 5.3 does not mean that a 1.0 will necessarily look "better"
Put another way, say we take three stones, a 1 HCA, 3 HCA and 5HCA and show them to a bunch of observers. The tool is not designed to put these stones in order. People will pick the 5 over the 1, and others will pick the 3 over the 1.

It's interesting to have Kenny make insinuations about me being some sort of devil trying to make money off a discussion like this by obscuring facts- but the truth is, dealers of super ideals love to promote the idea that they're automatically better. I feel that is a disadvantage to consumers. I know and love Wink- he clearly has experience that leads him to look at this in a way that favors Super Ideal cut. But not everyone shares that preference. And the proportions of people picking the smaller table "Super Ideal" over a super well cut 60/60 are going to be close to 50/50 in my experience. Keep in mind we sell BOTH super ideal and "normal" super well cut. So I'm not trying to convince people one way or the other
 
Rockdiamond said:
hi gm89uk! I am extremely familiar with HCA, and I did "poo poo" it out of hand at first. Years ago.
Since then I've learned a lot.
The HCA is a remarkable invention and does a great job.
But it does not work in the manner you're implying.
It's a rejection tool for buying online, where you can't see the diamonds.
Stones that score low ( well) on HCA have a consistently nice look.
In terms of what it does reject, I still have issues.
Simply because a stone is 5.3 does not mean that a 1.0 will necessarily look "better"
Put another way, say we take three stones, a 1 HCA, 3 HCA and 5HCA and show them to a bunch of observers. The tool is not designed to put these stones in order. People will pick the 5 over the 1, and others will pick the 3 over the 1.
Click to expand...

Hey Rickdiamond, I'm aware that HCA is a rejection tool and their are many proportions that score 2 to 4 that I'd prefer to others that score less than 2. For example id much rather. 35/41, 35.5/40.8 even a 35.5/41 over a 33/40.5. But then HCA is not just for erings and I see it purely as a means to calculate theoretical light return which as you have many times discussed is only one attribute and does not dictate beauty. I understand all that.

I apologise if I was vague in my comments, I was commenting on two particular stones where one was 5.3 and the other 1.3, not a generalisation. Also I was expressing my particular opinion on a stone with 41.6 pav which I have seen before and not liked.

I have seen lots of stones although not a drop of a vendors experience. I have a strong preference for lower HCA stones, particularly when viewed outside the store lights. Your examples of people preferring 5 and 3 are quite arbitrary without any proportions, other vendors stated they have blind tested their customers with strong preference to super ideal proportions in general in the majority. Unfortunately I know of no controlled double blind study so further chat is just individual experience of both vendors and consumers alike. As to hinting vendors of financial incentives, it works both ways and I think it's useful to have variation of opinion and the ability to be able to express as such without such comments; although I feel you hinted in a similar fashion towards superideal vendors. I apologise if I misinterpreted
 
Why chase AGS?
What you are doing will already reduce value. If you want a future improved resale value then do nothing
 
Garry H (Cut Nut) said:
The simplest least weight loss is to cut the pavilion only to around 41.1 degrees.
This will drop the weight below 1.20ct which causes an economic loss of +5% because there is a small weight catagory jump at 1.20ct.
Weight loss doing pavilion only will be 0.01 to 0.02ct.
the stone would end up close to David's Rock n Roll 60:60
Click to expand...

Thank you for the information, Garry. In your opinion, would it be worth re-cutting this stone to those specifications? Is re-cutting just the pavilion less risky?
 
If you recut the crown to get a smaller table and ideal crown angle you will loose heaps of weight and diameter.
 
To clarify: at the moment you have a 33.5/41.6 60/61.3 thats a 1.2 carat.

That puts the girdle somewhere around 3.67% with a diameter around 6.845mm.
If you reduced the pavilion to 41 then the depth would reduce to roughly 60.4% and the carat weight to 1.186. This would reduce your diamond from 1.20 to probably 1.18 on the report. There is a price jump in carat weights >= 1.2 and as yours is on the border, your diamond would devalue. This is best case scenario with perfect cutting.

These numbers may be off due to GIA rounding.

If it was a 1.24 ct diamond, it would be safer to recut and stay in the 1.2+ carat bracket.
 
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