Is this an Ideal cut?

[Stephan]

Date: 4/23/2009 6:30:55 PM
Author: strmrdr
The entire idea is not correct by themselves lower and upper angles mean nothing and even relative to each other mean little.

I don''t think so.
Not only the middle but also the perimeter of the diamond should be alive (fire + light return), that makes a diamond look big.

Date: 4/23/2009 6:30:55 PM
Author: strmrdr
For example lower angle and length has to be considered against table size and crown height(CA is not 100% correct for this but can be used) not the upper girdle angle.
For every table size and crown height there is a different set of lowers that are optimal.
Then once that is done you have to balance them against the mains to see if they are practical(min painting and digging)

I totally agree.
Note that more than minimal painting or digging out will be mentioned on the GIA report.

Date: 4/23/2009 6:30:55 PM
Author: strmrdr
The upper girdle angle has to be balanced against the lowers, mains,CH, CA, and table.

I still agree

Date: 4/23/2009 6:30:55 PM
Author: strmrdr
Even if you were correct trying to calculate it from even non-gia rounded numbers is bad data.

You should not say bad, but imprecise.
Yet we can''t do better and the data I used is the best we can do if GIA doesn''t mention painting/digging.

Karl,

I know you had a diamond cut to your design.
I also know you bought Diamond Calc.
I respect your talents in matter of mathematics.
But I don''t know how many round brilliants you saw in real life.
And how many types of round brilliants.
Because if you saw 500 H&A''s, it only will tell you a part of the story.
As you told, till now Diamond Calc is not able to evaluate fire properly.
Diamond Calc won''t tell you if the color you see in the picture will be noticed as a big intense flash from the other side of the street or if it will be weak and only noticed from you when staring at your ring from a 25 cm distance.
I think Diamond Calc is interesting to estimate patterns due to reflections, to measure light return, but flashes of fire that occult a diamond because they are so strong is something Diamond Calc developers have to work on.
I really don''t want to aggress you, the fact is you aggress people by using words as "nonsense". When I say "I prefer" you say "You are wrong". When I say "I think that" you say "The truth is that".
Karl,
When you want, let your computer home and come to Belgium, my country.
I''ll show you Antwerp, it''s a place where you can look at diamonds from 10AM to 6PM every day but Sunday.
Karl you are great but a little humility could suit you.
I don''t know what time it is but here it''s time to go to bed.
Now you have plenty of time to reply.

 

[strmrdr]

Stephan,
You agree but totally miss my point.
Let me try again, lower angle and upper angle numbers by themselves are meaningless.
They have to considered relative to everything else on the diamond.
The optimal angle will vary depending on the rest of the diamond.

When it comes to getting factual and complete information out there I have little humility is true.
As far as the number of diamonds I have seen over the years the total is in the thousands.

good night and sweet dreams

 

[oneeyejack]

sandystone: on a completely unrelated note, i was just wondering why you are limiting your diamond search to BN? i might have missed something that you posted in another thread, but there are so many other vendors out there in which you can get an IS and pictures of the diamond.

just wonderin....

 

[Stephan]

Karl,
Yes I missed something, sorry for that.
I can see your point now.
I would be pleased if you try to create some charts of what should go with what following you.
I know it isn''t easy (same for Facetware, HCA) because of the huge amount of combinations, but I''m sure you can make it.
I always had the idea there were bad lower/upper girdle combos, independent of the rest of the diamond.
For example 39 upper with 41.8 lower that would be too shallow or 43 upper with 42.2 lower that would be to steep/deep.
Most surface of the diamond (without the table) is covered by minor facets and we all need to know the way we should consider them.

 

[strmrdr]

Date: 4/24/2009 3:11:27 AM
Author: QueenMum
Karl,

Yes I missed something, sorry for that.

I can see your point now.

I would be pleased if you try to create some charts of what should go with what following you.

I know it isn''t easy (same for Facetware, HCA) because of the huge amount of combinations, but I''m sure you can make it.

I always had the idea there were bad lower/upper girdle combos, independent of the rest of the diamond.

For example 39 upper with 41.8 lower that would be too shallow or 43 upper with 42.2 lower that would be to steep/deep.

Most surface of the diamond (without the table) is covered by minor facets and we all need to know the way we should consider them.

let me think about this.
I will look into doing it.
For one c/p/t combo it isn''t a huge problem but it is a lot of data.
A chart for a bunch of combos would take more time than I have.

 

[sandystone1]

Hi Oneeyejack.....actually the reason I am looking mainly at BN is because I have seen very very few vendors who actually provide financing and who also have average prices. If a vendor is cheaper, there is no financing, on the other hand if he has financing, it is expensive......let me know if know any good retailers out there, I would be more than happy to look at them.

Thanks
Sandy

 

[Stephan]

Hi Sandy!
Did you order something?

 

[sandystone1]

Still holding on 3 & 4 both.....I was gonna do it today, but got stuck in some work. I will do it over the weekend I guess

 

[Stephan]

What a suspense!

 

[sandystone1]

I know Stephan....believe me....even if I buy it, it will still be a suspense for me

 

[Stephan]

Date: 4/24/2009 2:27:28 PM
Author: sandystone1
I know Stephan....believe me....even if I buy it, it will still be a suspense for me

I''m impatient to see what you''ve chosen.

 

[sandystone1]

Hi Stephan, Karl, Lorlie,

During the weekend I did some more research & search and found an identical stone to the one I liked as my second choice.

1.42 G VVS2 Med-Sl Thk 0.9 HCA 61.8 56 35/40.6 (7.22 x 7.19 x 4.45 mm) Star 50% Lower Depth 80%

If you guys can please go to the following link, you will see it has images (click on GCAL report) that show it is a signature ideal diamond.

http://www.bluenile.com/round-diamond-1-carat-signature-ideal-cut-g-color-vs1-clarity_LD01072000?__fun_frm=i&filter_id=0

All the combos, depth, table are identical to the one I have above. My question to you all is, if this BN one is good, will my stone have almost same performances? The only diff in both is the size.

Thanks
Sandy

 

[Stephan]

Date: 4/27/2009 1:50:52 PM
Author: sandystone1
My question to you all is, if this BN one is good, will my stone have almost same performances? The only diff in both is the size.

Another difference is depth.
The diamond you''ve ordered isn''t as deep, and I think it''s a good thing.
Now for the pattern or the performances, we can''t tell you if it is similar: GIA numbers are rounded.
With BlueNile, no other possibility to wait for your diamond and:
~ you see it you love it you keep it
~ you see it you hate it you send it back
or
~ you take it to an appraiser and ask him if he loves it
or
~ you buy an IdealScope

 

[Lorelei]

It has definite potential Sandy.

 

[Stephan]

Date: 4/27/2009 3:46:40 PM
Author: Lorelei
It has definite potential Sandy.

I think the same way too!

 

[strmrdr]

Pictures of a different diamond don''t tell you anything about another with simular rounded numbers.
The gcal pics look pretty good.

 

[sandystone1]

Thanks guys for the suggestions. I have 1.30 ct as my first choice, just thinking more about size as compared to 1.42.

 

[Stephan]

Sandy, you are killing me softly!

 

[sandystone1]

Hi Stephan, Karl & Lorlie,

I am sorry to bother you guys everytime I have a question and really appreciate you answering it. I am a little stubborn

....can''t help it....actually the main reason is I am getting all sort of diff answers and the confusing part is all of them make sense

BN and other websites have 60.1 - 61.9 depth as something better than ideal (Hearts & Arrows).....so let me ask you all this....lets say the 1.42 ct stone might leak light, how much of a performance diff are we talking about here? Will their be a major diff or slight....if it is slight, I am willing to take that chance for additional size & clarity....also I know thin-med is better than med-sl thick. But how much of a diff will it make....is med-sl thick really bad to be considered?

I know it is not fair to ask for an opinion without images, but can you comment based on your experiences with such specs....

Here are both the specs again:

1.30 G VS1 Med faceted 0.9 HCA 61.3 57 35/40.6 (7.03 x 7.01 x 4.30 mm) Star 50% Lower Depth 80%
1.42 G VVS2 Med-Sl Thk Faceted 0.9 HCA 61.8 56 35/40.6 (7.22 x 7.19 x 4.45 mm) Star 50% Lower Depth 80%

Thanks Guys
Sandy

 

[Stephan]

~ VS1 will be eye clean as VVS2 but cheaper
~ I prefer medium girdle to slightly thick
Give me the 1.3ct and save some money.
Size difference won''t be big between those two.

 

[Lorelei]

Date: 4/27/2009 6:58:41 PM
Author: sandystone1
Hi Stephan, Karl & Lorlie,

I am sorry to bother you guys everytime I have a question and really appreciate you answering it. I am a little stubborn

....can't help it....actually the main reason is I am getting all sort of diff answers and the confusing part is all of them make sense

BN and other websites have 60.1 - 61.9 depth as something better than ideal (Hearts & Arrows).....so let me ask you all this....lets say the 1.42 ct stone might leak light, how much of a performance diff are we talking about here? Will their be a major diff or slight....if it is slight, I am willing to take that chance for additional size & clarity....also I know thin-med is better than med-sl thick. But how much of a diff will it make....is med-sl thick really bad to be considered?

I know it is not fair to ask for an opinion without images, but can you comment based on your experiences with such specs....

Here are both the specs again:

1.30 G VS1 Med faceted 0.9 HCA 61.3 57 35/40.6 (7.03 x 7.01 x 4.30 mm) Star 50% Lower Depth 80%
1.42 G VVS2 Med-Sl Thk Faceted 0.9 HCA 61.8 56 35/40.6 (7.22 x 7.19 x 4.45 mm) Star 50% Lower Depth 80%

Thanks Guys
Sandy

Hi Sandy,

Depth is not a determining factor as to how the light reflects through the diamond and therefore beauty, I wouldn't think either of those would leak based on the info given.

 

[sandystone1]

Hi Guys,

Even if the combo is rounded how much down/up can these nos. go? Currently it is 35/40.6, does it go only 0.20 down or more than that? Like 35/40.6 becomes 34.8/40.4 or even more down?

If it goes down only by 0.20 on either or both, then the 4 only combinations I will have are:
35/40.4 (is it good or bad?)
34.8/40.4 (is it good or bad?)
34/40.6 (is it good or bad?)
35/40.6 (is it good or bad?)

Also, I have seen a lot of expensive stones with a combo of 35.5/40.6 for 61.8/56 D/T. Is this a more exceptable combo for this depth/table?


Thanks Sandy

 

[Lorelei]

Date: 4/28/2009 10:02:22 AM
Author: sandystone1
Hi Guys,

Even if the combo is rounded how much down/up can these nos. go? Currently it is 35/40.6, does it go only 0.20 down or more than that? Like 35/40.6 becomes 34.8/40.4 or even more down?

If it goes down only by 0.20 on either or both, then the 4 only combinations I will have are:
35/40.4 (is it good or bad?)
34.8/40.4 (is it good or bad?)
34/40.6 (is it good or bad?)
35/40.6 (is it good or bad?)

Also, I have seen a lot of expensive stones with a combo of 35.5/40.6 for 61.8/56 D/T. Is this a more exceptable combo for this depth/table?


Thanks Sandy

This thread explains rounding Sandy,

https://www.pricescope.com/community/threads/consumer-advisory-gia-cut-grade-rounding-problems.39401/

Remember also that yes the above combo might work well but there can be variances and there is info we are missing so Idealscope or ASET are really the best way to tell how a given configuration works for a particular diamond.

 

[JA72]

Date: 4/18/2009 12:48:07 PM
Author: QueenMum

But my favorite diamond is not branded, and it has a 58% table.
If well cut, a 59.5% depth diamond with a ''big'' table (58%) will look bigger and more scintillating than an ''ideal'' marketed diamond.

Hi QueenMum,

Can you post a picture of your favorite diamond, the 58% table and 59.5% depth? You mentioned it is your favorite. How is the fire on this stone? Can you tell me why it is your favorite and how it performs?

Excited because a diamond I am about to purchase sounds very similar in proportions to the one you mentioned being

your favorite.

Thanks

 

[Stephan]

Date: 4/28/2009 10:28:55 PM
Author: JA72
Can you post a picture of your favorite diamond, the 58% table and 59.5% depth? You mentioned it is your favorite. How is the fire on this stone? Can you tell me why it is your favorite and how it performs?

The 0.64ct N-VVS1 I was talking about? I left to my ex, so no picture.

At the same time, I had a 1.15 J-VS1 H&A cut by Muller (Antwerp), it was a H&A and was a De Beers Millenium diamond, really nice.
But most H&A I''ve seen (and bought) have 1 big flash of fire at a time and some pinpoint fire.
The 0.64ct had more and bigger flashes at a time, and the fire was more intense.
It made the diamond look bigger than the Millenium H&A when standing in front of a mirror with lights from a +/- 3m distance. The scintillation was faster too: there was always something happening.

Date: 4/28/2009 10:28:55 PM
Author: JA72
Excited because a diamond I am about to purchase sounds very similar in proportions to the one you mentioned being your favorite.

There are so many factors that it is hard to tell if they will be similar.
Mine had long star facets and long lower halves.

 

[JA72]

Thanks QM

Mine has a star 50 and lower 78.

 

[sandystone1]

Hi Guys,

The stone I was about to buy was sold out. Looks like some was quicker than me

.....Anyways what is your opinion about this one:

1.55 G VS2 Med - slthk 61.4/57 35/40.6 HCA 0.9 50% Star 80% LD

Also it says 8Hearts & 8Arrows as comment on the Gia cert.

Thanks
Sandy

 

[Stephan]

Hi Sandy!
Do you have a link to it?
It sound good.

 

[sandystone1]

Thanks Stephan,

The reason I didn''t gave the link is coz I dont want this to be sold out too

.....I know you like less deep stones and the combo on this one is same as 35/40.6 with HCA of 0.9 & med - slthk griddle.

Does the best cut diamond has 8 Hearts & 8 Arrows? Also if it is written on Gia cert, should I assume it has it?

Thanks
Sandy

 

[Stephan]

Inscription ''H&A'' is worth nothing.
What is the date of the certificate?
The measurements (in mm)?
Is there something written under ''Comments''?
What and where are the inclusions?
What about fluorescence?