Girdle Question

[JA72]

Hi,

I inputted the specs into the HCA calculator of a diamond I am interested in. When I hit submit, it changes the table % rounding it up. I would like to know what everyone thinks of this diamond and any areas of concern you may have after seeing the specs. Also, I would like to know how the girdle will affect the performance of this diamond since it varies greatly from thin to thick. Will this girdle affect the HCA rate? I am guessing not since the girdle is not factored into the HCA calculator. Thanks

1.32ct
7.17 x 7.18 x 4.27mm
Ideal cut
F (VVS1)

Table 58.5
Depth 59.5
Crown angle 32.6
Pavillion angle 41.0
Girdle (faceted) 1.0-3.1%
Culet Pointed

Please let me know how you think this will perform and if there are any areas that are not so great.

Thank you

 

[Lorelei]

Date: 4/6/2009 8:12:19 AM
Author:JA72
Hi,

I inputted the specs into the HCA calculator of a diamond I am interested in. When I hit submit, it changes the table % rounding it up. I would like to know what everyone thinks of this diamond and any areas of concern you may have after seeing the specs. Also, I would like to know how the girdle will affect the performance of this diamond since it varies greatly from thin to thick. Will this girdle affect the HCA rate? I am guessing not since the girdle is not factored into the HCA calculator. Thanks

1.32ct
7.17 x 7.18 x 4.27mm
Ideal cut
F (VVS1)

Table 58.5
Depth 59.5
Crown angle 32.6
Pavillion angle 41.0
Girdle (faceted) 1.0-3.1%
Culet Pointed

Please let me know how you think this will perform and if there are any areas that are not so great.

Thank you

Hi J,

I didn't find it rounded the table in this case for the actual score - for the score chart it did for categorizing which range for GIA or AGS on the right of the HCA page - but also it isn't used to select diamonds but to eliminate those which are lesser performers. Does this diamond have an AGS or GIA report?

The diamond looks promising but do you have any images such as Idealscope or ASET we can see to evaluate the diamond further? Have you seen the diamond in person? What are the polish and symmetry grades also please? The girdle percent going by my chart is fine at thin to medium, in a very good range so no worries there. Also the girdle does not affect the HCA score, the HCA is limited that it can only really tell you which diamonds are worth further investigation and which ones are not.

It is hard to predict with any certainty how a diamond will perform from a few numbers, the shallow crown angle suggests this could be a very bright and brilliant diamond primarily, fire may not be the highest but the best way to find out is to check with the vendor if you trust their opinion or see the diamond in person and compare with some others, I would suggest to compare with AGS0 Peerless brand from Jareds or Hearts on Fire if there is a seller near you.

Also I just wanted to mention unless you really wanted a colourless VVS diamond, you could lower both colour and clarity without visual sacrifice if the cut is great, but this is only a suggestion and it comes down to personal preference.

 

[JA72]

Thanks for the quick reply Lorelei.

Nope, haven't seen it. It's an e-diamond with an AGSL. Cut Ideal, Polish/Sym both Ideal, triple 0's. When I put in the table it rounded up to 59% on the result page. At that, it still rated .9 but that is assuming it has a medium girdle. No aset or sarin provided.

I don't know how much the girdle plays in the performance of the diamond.

Thanks again, hope to hear back from all of you.

Oh, almost forgot. Fire is very important to me, you mentioned that it might not be the highest, but when I put the numbers into HCA it said excellent straight acrossed the board but that is with the weird phenomenon of the rounding up issue. I tried it again and it did it again. Since it didn't adjust on your end, what was the score that you received?

 

[Lorelei]

Date: 4/6/2009 8:30:28 AM
Author: JA72
Thanks for the quick reply Lorelei.

Nope, haven''t seen it. It''s an e-diamond with an AGSL. Cut Ideal, Polish/Sym both Ideal, triple 0''s. When I put in the table it rounded up to 59% on the result page. At that, it still rated .9 but that is assuming it has a medium girdle. No aset or sarin provided.

I don''t know how much the girdle plays in the performance of the diamond.

Thanks again, hope to hear back from all of you.

Just checking, the diamond has the AGS0 Ideal cut grade and a Diamond Quality Document? Which vendor has it if you don''t mind me asking, would it be Blue Nile?

 

[Lorelei]

Date: 4/6/2009 8:30:28 AM
Author: JA72
Thanks for the quick reply Lorelei.

Nope, haven't seen it. It's an e-diamond with an AGSL. Cut Ideal, Polish/Sym both Ideal, triple 0's. When I put in the table it rounded up to 59% on the result page. At that, it still rated .9 but that is assuming it has a medium girdle. No aset or sarin provided.

I don't know how much the girdle plays in the performance of the diamond.

Thanks again, hope to hear back from all of you.

Oh, almost forgot. Fire is very important to me, you mentioned that it might not be the highest, but when I put the numbers into HCA it said excellent straight acrossed the board but that is with the weird phenomenon of the rounding up issue. I tried it again and it did it again. Since it didn't adjust on your end, what was the score that you received?

Bear in mind this is just an estimation with the fire, the numbers suggest it might not be the most fiery diamond but this might not be accurate in reality.

HCA -

depth - 59.5%
table - 58.5%
crown angle 32.6
pavilion angle 41


I think I was looking at the wrong area for the HCA rounding initially so you are right, it does round for the score chart and indeed scored 0.9 within TIC range ( Tolkowsky Ideal Cut) outside of the AGS0 box and within GIA Excellent. As for the rounding when estimating which category the diamond will fall within, but I wouldn't worry too much, the angles are the critical thing here and if you could get an image such as Idealscope, that would be far more useful than the HCA.

 

[JA72]

It is from BN. I have it on hold now . The rep was very helpful and explained that compared to a "classic" model of a diamond, this was cut more for fire than scintillation (yet assured me that being an AGSL ideal that there will still be great scintillation). He mentioned that the depth being under 60 and the table being over 57 he can tell it was cut for fire and not scintillation. Is this what they call a shallow diamond??? not sure about the term but I will have to research more on things like fisheye etc.

Also, I am wondering, which do you prefer, more fire or more scintillation?

Since it isn''t inscribed, that will be my next decision, whether to have it sent away for inscription before buying it. I have purchased BN before and never had to send one back, but I love their return policy. If I don''t like the performance or if the scintillation just isn''t there I can return it for a full refund.

Has anyone had any bad experiences sending one back to BN for a refund? I worry about such an expensive piece being sent back.... worried that the postman or receptionist might "lose" it on its way back if that is what I end up doing.

What to do.... diamond shopping can be so stressful LOL

 

[Lorelei]

Date: 4/6/2009 9:56:07 AM
Author: JA72
It is from BN. I have it on hold now . The rep was very helpful and explained that compared to a 'classic' model of a diamond, this was cut more for fire than scintillation (yet assured me that being an AGSL ideal that there will still be great scintillation). He mentioned that the depth being under 60 and the table being over 57 he can tell it was cut for fire and not scintillation. Is this what they call a shallow diamond??? not sure about the term but I will have to research more on things like fisheye etc.

Also, I am wondering, which do you prefer, more fire or more scintillation?

Since it isn't inscribed, that will be my next decision, whether to have it sent away for inscription before buying it. I have purchased BN before and never had to send one back, but I love their return policy. If I don't like the performance or if the scintillation just isn't there I can return it for a full refund.

Has anyone had any bad experiences sending one back to BN for a refund? I worry about such an expensive piece being sent back.... worried that the postman or receptionist might 'lose' it on its way back if that is what I end up doing.

What to do.... diamond shopping can be so stressful LOL

Umm..I don't know where he is getting his info from there

...A diamond which is cut for fire usually has a steeper crown angle of about 35.5 plus unlike this one which is shallow, with a pavilion angle of no more than 40.6. You also find fiery cut diamonds can have some greater depth and a small table so really with respect what this rep is saying does not make sense. This diamond is not cut for fire.

If you particularly want a fiery diamond then I wouldn't choose this one, but another which is far more conducive to show fire as I detailed above. Scintillation is the intense sparkly ' flashy' effect you see when the diamond is in motion caused by the on off effect of the diamonds facets, see more here. Don't go by the HCA as any real prediction of any amount of scintillation that a diamond will show, suffice to say a well cut and clean diamond will have plenty.

http://diamonds.pricescope.com/brill.asp

Do you have the link for the diamond or can you post the grading report please?

If you are in the US then it is usual to return a diamond using USPS Registered mail, I believe most of the vendors require customers to use this method for returns. You have to pack and tape the package in a certain manner, this mailing method is slow but very secure - so just follow the instructions BN give you should you need to return the diamond.

As to a fish eye by all means read up on this but it is rare that a relatively well cut diamond will show this effect.

http://diamonds.pricescope.com/fisheye.asp

 

[Stone-cold11]

Agreed. Sounds like the SA is just sprouting nonsense to make a sale.

 

[JA72]

Here you go Let me know what you think on all aspects of the diamond. http://www.bluenile.com/round-diamond-1-carat-ideal-cut-f-color-vvs2-clarity_LD01118119 .

Now I am really confused. I have no idea how this diamond is going to perform. I want a balance of fire and scintillation. I thought HCA was very dependable, when I saw excellent acrossed the board, I got really excited. I guess the search might not be over....

Thanks for your expert advice on this.

 

[Lorelei]

Date: 4/6/2009 10:16:12 AM
Author: JA72
Here you go Let me know what you think on all aspects of the diamond. http://www.bluenile.com/round-diamond-1-carat-ideal-cut-f-color-vvs2-clarity_LD01118119 .

Now I am really confused. I have no idea how this diamond is going to perform. I want a balance of fire and scintillation. I thought HCA was very dependable, when I saw excellent acrossed the board, I got really excited. I guess the search might not be over....

Thanks for your expert advice on this.

Thanks! I will check the link out. Sorry but if you want a fiery diamond - despite what the BN rep is telling you, this diamond is not cut for fire.

The HCA is an incredibly useful tool but its purpose is for elimination only, not selection. It can't predict the performance or behaviour of any diamond with accuracy, just let you know if a diamond is worth further evaluation or not, then this is done with ASET and or Idealscope images plus a trusted expert's eyes, then ultimately your own! I checked the link out, if falls outside of the AGS Ideal box on the HCA but this does happen sometimes. If you like and you decide against this diamond, maybe we could try to find some others which might give you a good display of fire that you really want?

Also concerning the thin to thick girdle measurement, this is a glitch on the BN website, for some reason AGS girdle percents often seem to get graded thin to thick on the diamond's description from BN.

 

[Ellen]

Date: 4/6/2009 10:00:42 AM
Author: Lorelei

Umm..I don''t know where he is getting his info from there

...A diamond which is cut for fire usually has a steeper crown angle of about 35.5 plus unlike this one which is shallow, with a pavilion angle of no more than 40.6. You also find fiery cut diamonds can have some greater depth and a small table so really with respect what this rep is saying does not make sense. This diamond is not cut for fire.

If you particularly want a fiery diamond then I wouldn''t choose this one, but another which is far more conducive to show fire as I detailed above. Scintillation is the intense sparkly '' flashy'' effect you see when the diamond is in motion caused by the on off effect of the diamonds facets, see more here. Don''t go by the HCA as any real prediction of any amount of scintillation that a diamond will show, suffice to say a well cut and clean diamond will have plenty.

http://diamonds.pricescope.com/brill.asp

Do you have the link for the diamond or can you post the grading report please?

If you are in the US then it is usual to return a diamond using USPS Registered mail, I believe most of the vendors require customers to use this method for returns. You have to pack and tape the package in a certain manner, this mailing method is slow but very secure - so just follow the instructions BN give you should you need to return the diamond.

As to a fish eye by all means read up on this but it is rare that a relatively well cut diamond will show this effect.

http://diamonds.pricescope.com/fisheye.asp

I wouldn''t either. And the SA doesn''t know what they are talking about.

Are you open to any other online vendors? (that also have great return policies)

 

[JA72]

Thank you all so much for the input. Doesn''t being graded as tripple zeros and ideal acrossed the board by AGSL pretty much guarantee that it will perform ideally? If not, then I am really confused about even the importance of a grading by AGSL... which I have been told and read is the top of the grading houses.....

 

[Lorelei]

Date: 4/6/2009 10:37:36 AM
Author: JA72
Thank you all so much for the input. Doesn't being graded as tripple zeros and ideal acrossed the board by AGSL pretty much guarantee that it will perform ideally? If not, then I am really confused about even the importance of a grading by AGSL... which I have been told and read is the top of the grading houses.....

AGS0 cut grade diamonds are for the most part well cut and should perform well, yes AGS are considered to be very strict and are valued for cut grading. This diamond could be a good performer but the thing is that the proportions working together can help a diamond display all the things we value in it, brilliance, fire, scintillation and so on. If you compare two faces, each have two eyes, a nose and a mouth - both can look very different even though they consist of the same basic ' ingredients.' And so it can be with diamonds, the differences are far more subtle but still there. Certain proportions can be preferred as they can help a diamond show more fire, more brilliance etc - the diamond you are considering will most probably show more brillance than fire as I explained above. It could be a good looking stone, but not show as much in the way of fire that you would like. You can read more on this here -

http://www.diamond-cut.com.au/23_bicfic.htm

 

[JA72]

Thanks, it is starting to look more and more clear. That link and your comments have been very helpful. I think I will head to a B&M with in the next few days to see which I really prefer, Scin or Fire then resume my search online So, to recap, if I want a more firey diamond then I need to look for a crown angle of around 35.5 with a pavillion of 40.6? I need to do more research. I knew there was a lot to know about diamonds, but finding the balance with so many variables is enough to make a lay-person go insane! LOL I want my diamond to look great in the sun, in doors and at night. I notice my current signature ideal looks best in restaurants at night but isn''t as firey as I would have liked.

 

[Lorelei]

Date: 4/6/2009 11:01:29 AM
Author: JA72
Thanks, it is starting to look more and more clear. That link and your comments have been very helpful. I think I will head to a B&M with in the next few days to see which I really prefer, Scin or Fire then resume my search online So, to recap, if I want a more firey diamond then I need to look for a crown angle of around 35.5 with a pavillion of 40.6? I need to do more research. I knew there was a lot to know about diamonds, but finding the balance with so many variables is enough to make a lay-person go insane! LOL I want my diamond to look great in the sun, in doors and at night. I notice my current signature ideal looks best in restaurants at night but isn't as firey as I would have liked.

Yes with a fiery ideal cut, the aim is to get a steep crown angle of 35.5 or above along with a pavilion angle of no more than 40.6. This is important as a steep pavilion angle along with a steep crown can lead to light leakage and this we don't want. This link here is useful for going into more detail.

http://www.diamond-cut.com.au/23_bicfic.htm

I would compare with some AGS0 such as Jared Peerless or Hearts on Fire if these are conveniently located as you might find just a well cut and balanced diamond will do the job nicely for you rather than actually pursuing a fiery ideal cut type. The best thing is to really look and compare so you know what you like best. As to scintillation most well cut diamonds will show a good amount, so I would tend to compare the all over performance of each diamond. I know it can be a bit confusing but we will try to keep it as easy as possible but now you are on your way to finding a diamond you will really love - so you are doing fine! Also if you like we can suggest some diamonds which might suit you from the online vendors.

 

[Stone-cold11]

I think also try to look for smaller lower girdle facets numbers to get more fire.

 

[JA72]

I think you are all right. I told BN to remove the hold on this stone. I guess it is a safe bet that if I want a happy medium to look for a crown angle of 33.5-34.5. in that case, what should the limits be on the pavillion angle to make sure there is minimal leakage? I will read up on the links you provided and when I "think" I have found one I love I will be sure to post again for your expert opinons. Thanks GOD there is a place like pricescope to go for advice. I was just about to tell my husband that I found the one before I got the scoop here. Thank you for saving me time and energy ... I think I would have returned it after seeing it in person.

 

[Lorelei]

Date: 4/6/2009 11:30:14 AM
Author: JA72
I think you are all right. I told BN to remove the hold on this stone. I guess it is a safe bet that if I want a happy medium to look for a crown angle of 33.5-34.5. in that case, what should the limits be on the pavillion angle to make sure there is minimal leakage? I will read up on the links you provided and when I 'think' I have found one I love I will be sure to post again for your expert opinons. Thanks GOD there is a place like pricescope to go for advice. I was just about to tell my husband that I found the one before I got the scoop here. Thank you for saving me time and energy ... I think I would have returned it after seeing it in person.

Yes concentrate on the angle ranges more than lower girdle facets at this stage to keep things simple. The angles and table size ( look for 54- 57 table) are the critical factors here. With the pavilion angle aim for around 40.6 or a little less for a fiery ideal cut, any steeper then the angles might not work so well together and result in leakage so with the numbers I mentioned you should be pretty safe. Crown angle for fire, I would suggest 35 degrees and up, some fiery ideal cuts have angles of 36 degrees and higher along with the pavilion angle as above.

For a happy medium with a diamond, here are some numbers some of us use to find a balanced well cut round diamond.

depth - 60 - 62% - although my personal preference is to allow up to 62.4%
table - 54- 57%
crown angle - 34- 35 degrees
pavilion angle - 40.6- 41 degrees
girdle - avoid extremes, look for thin to slightly thick, thin to medium etc
polish and symmetry - very good and above

note - with crown and pavilion angles at the shallower ends ( CA 34- PA 40.6) and steeper ( CA 35- PA 41) check to make sure these angles complement in that particular diamond - eyeballs, Idealscope, trusted vendor input - check as appropriate!

As the above implies, configurations depend on each other. A little give here can still work with a little take there.

From expert John Pollard.

With that said, here's a "Cliff's Notes" for staying near complementary angles with GIA reports (their numbers are rounded): A crown angle of 34.0, 34.5 or 35.0 is usually safe with a 40.8 pavilion angle. If pavilion angle = 40.6 lean toward a 34.5-35.0 crown. If pavilion angle = 41 lean toward a 34.0-34.5 crown.

GIA "EX" in cut is great at its heart, but it ranges a bit wider than some people prefer, particularly in deep combinations (pavilion > 41 with crown > 35).


And please post any contenders you like and we can take a look for you! I am glad you released the other diamond, I am sure it wouldn't have given you what you wanted. And do compare some in person, as I say a well cut AGS0 with tighter crown and pavilion angles might be a good choice for you too.

Also with fire, bear in mind that you will see it mainly if the lighting is right, it isn't something you will notice all the time - but if your diamond is clean and well cut you will see it burst forth in some lighting.

 

[JA72]

"Also with fire, bear in mind that you will see it mainly if the lighting is right, it isn''t something you will notice all the time - but if your diamond is clean and well cut you will see it burst forth in some lighting."

Today, after going over all the great information you provided me I re-read the line above. Since fire is fleeting, only under right conditions, wouldn''t it be better to pick a diamond that isn''t cut mainly to focus on fire? Since you can''t have great scintillation and great fire (if I am not totally screwing this up), then wouldn''t a diamond cut more for scintillation produce more often than waiting for ideal conditions to get that fire (in the right lighting?).... Thanks

 

[Lorelei]

Date: 4/7/2009 12:14:38 AM
Author: JA72
'Also with fire, bear in mind that you will see it mainly if the lighting is right, it isn't something you will notice all the time - but if your diamond is clean and well cut you will see it burst forth in some lighting.'

Today, after going over all the great information you provided me I re-read the line above. Since fire is fleeting, only under right conditions, wouldn't it be better to pick a diamond that isn't cut mainly to focus on fire? Since you can't have great scintillation and great fire (if I am not totally screwing this up), then wouldn't a diamond cut more for scintillation produce more often than waiting for ideal conditions to get that fire (in the right lighting?).... Thanks

All diamonds will show scintillation which are the intense sparkles you see when the diamond is moving. Most well cut diamonds will show fire to a certain extent. Diamonds aren't cut specially for scintillation as far as I am aware. All diamonds are dependant on the light they have to work with, they won't sparkle that much if there isn't any light available. You could certainly pick a diamond which is a fiery ideal cut if that is what you preferred but I would really recommend you look at some well cut diamonds in person , such as the AGS0 from Jareds or Hearts on Fire to see how you like a well cut and balanced diamond in person. You might find the fire aspect is quite sufficient.