Do rounds ''look'' bigger than princesses?

[dalan71]

I was looking at round and princess Signature-Ideal cuts on Blue Nile. Looking at the GCAL reports they have for their Signature-Ideal cuts, they have "actual size" photos. To me, the ROUND 1.05 carat I was looking at appeared to look similar in size as a 1.5 carat PRINCESS cut I was also looking at. So, this begged the question....is this an optical illusion? Does the natural shape of a round tend to "appear" bigger than the princess shape? (assuming all things being equal...carat weight, etc.)

 

[Skippy123]

Hello, this chart may help you http://images.amazon.com/media/i3d/01/actual-diamond-size.pdf

 

[mpark46]

I am by no means an expert, but when I went to go look at diamonds, the jeweler we saw said that 2 diamonds (RB & any other shape really) all things being equal, the RB would be about 5% more expensive. I guess you need to cut more of the actual diamond on a RB to get the shape of it, hence the price difference (and larger looking stone).

 

[Jypsie]

Sorry - momentary topic derailing...

Skippy you are a lifesaver, if I wasn''t married I might actually love you for posting that chart! I have been looking for something exactly like this for awhile. Thank you thank you thank you!

Ok... back to the topic... I''ll step out, because I have no experience in this area, I only know what I''ve heard. Good luck!

 

[dalan71]

Thank you Skippy!!!! Also, mpark...thanks for th info. It seems rounds do tend be significantly more expensive.

 

[Skippy123]

Date: 12/18/2007 3:56:53 PM
Author: Jypsie
Sorry - momentary topic derailing...

Skippy you are a lifesaver, if I wasn''t married I might actually love you for posting that chart! I have been looking for something exactly like this for awhile. Thank you thank you thank you!

Ok... back to the topic... I''ll step out, because I have no experience in this area, I only know what I''ve heard. Good luck!

LOL

Glad it was a help to you and Dalan!!!

 

[vespergirl]

That''s a great chart that Skippy posted - I also think that rounds tend to look bigger because they reflect the most light.

That said, if your girl has her heart set on a square shape, I think that I princess will give you the most band for your buck - the pointed corners, set in v-shape prongs, give the optical look of adding larger face-up spread to the stone than the clipped-corner shapes, likes asschers and square radiants.

 

[brooklyngirl]

Your eyes were not fooling you. Rounds seem to have the best spread for their carat weight if cut properly. Princess cuts are deeper than RBs, so a lot their weight is concentrated in their dept, instead of their width.

 

[NeverEndingUpgrade]

What brooklyngirl said is what I have always heard. I have experienced it when looking at setting for square cut stones. Heads designed for a 1 ct. princess measure about 5.5 mm, but my 1 ct. Jubilee measures 6.06 mm. That''s a big difference in a ring setting!

 

[diamondseeker2006]

Yes, a round of the same carat weight will face up larger than a princess. So the greater cost is worth it, because the stone looks larger.

 

[DiamondExpert]

Here''s a pair of 1.57''s, both AGS0''s - the 1st pic (below) is "straight up".

 

[DiamondExpert]

...the 2nd one "on the rocks" - same stones.

 

[Garry H (Cut Nut)]

Good approach Gary

I have studies this several times from different approaches.
Princess cost less per carat
On a straight dollar per square millimeter of surface area there is not a lot in it (Valeria did a big survey of real stones a few years ago).

But on an edge of diamond light return basis - the rounds win hands down.

But if your lady wants Princess and you want to play frog, then good luck to you (you will need it!)

 

[Paul-Antwerp]

But a good cutter can emphasize certain light return-areas in a princess-cut to increase the edge-to-edge visual effect.

As in rounds, where a great cut will look bigger with the same diameter, one can do something similar in a princess-cut.

Live long,

 

[Garry H (Cut Nut)]

Date: 12/19/2007 3:59:25 AM
Author: Paul-Antwerp
But a good cutter can emphasize certain light return-areas in a princess-cut to increase the edge-to-edge visual effect.

As in rounds, where a great cut will look bigger with the same diameter, one can do something similar in a princess-cut.

Live long,

Yes Paul, you can emphasize the corners, or you can bring out the light return near the middle of the edges. But I have not seen a square brialiant cut style that has light return near the edges all around that will get that good a result.

But maybe we have,.... in the blue corner......a challenger.........?

 

[WinkHPD]

Date: 12/19/2007 4:21:53 AM
Author: Garry H (Cut Nut)

Date: 12/19/2007 3:59:25 AM
Author: Paul-Antwerp
But a good cutter can emphasize certain light return-areas in a princess-cut to increase the edge-to-edge visual effect.

As in rounds, where a great cut will look bigger with the same diameter, one can do something similar in a princess-cut.

Live long,

Yes Paul, you can emphasize the corners, or you can bring out the light return near the middle of the edges. But I have not seen a square brialiant cut style that has light return near the edges all around that will get that good a result.

But maybe we have,.... in the blue corner......a challenger.........?

Yes,

Our challanger, Paul, has asked me to post these two pictures for you from an unnamed cutter and supplier.

Here is a copy of his email, and in this and the next post I will place the accompaning photos.

Wink

I am horrible at uploading pics on PS.

Would like to upload following pics as a response to Garry''s challenge in this thread: https://www.pricescope.com/community/threads/do-rounds-look-bigger-than-princesses.74637/

Can you help me out?

I would like to write the following:

"And in the blue corner, with some apologies for the imperfect photography,
we have red ASET from corner to corner, emphasizing the long diameter of the square princess,
with red ASET areas at the corners, emphasizing edge-to-edge light return,
ladies and gentlemen, here are 2 fine examples of craftsmanship in cutting square princess-cuts:"

Live long,
Paul Slegers
Infinity Diamonds
www.CraftedByInfinity.com

P.S. I am downloading the file he labeled ASET2 first as the other one is too big and I need to go resize it.

 

[WinkHPD]

And finally, file reduction phone calls, and now file renaming...

I present to you ASET_1.

You are welcome Paul!

 

[Garry H (Cut Nut)]

Date: 12/19/2007 12:38:48 PM
Author: Wink

Date: 12/19/2007 4:21:53 AM
Author: Garry H (Cut Nut)

Date: 12/19/2007 3:59:25 AM
Author: Paul-Antwerp
But a good cutter can emphasize certain light return-areas in a princess-cut to increase the edge-to-edge visual effect.

As in rounds, where a great cut will look bigger with the same diameter, one can do something similar in a princess-cut.

Live long,

Yes Paul, you can emphasize the corners, or you can bring out the light return near the middle of the edges. But I have not seen a square brialiant cut style that has light return near the edges all around that will get that good a result.

But maybe we have,.... in the blue corner......a challenger.........?

Yes,

Our challanger, Paul, has asked me to post these two pictures for you from an unnamed cutter and supplier.

Here is a copy of his email, and in this and the next post I will place the accompaning photos.

Wink

I am horrible at uploading pics on PS.

Would like to upload following pics as a response to Garry''s challenge in this thread: https://www.pricescope.com/community/threads/do-rounds-look-bigger-than-princesses.74637/

Can you help me out?

I would like to write the following:

''And in the blue corner, with some apologies for the imperfect photography,
we have red ASET from corner to corner, emphasizing the long diameter of the square princess,
with red ASET areas at the corners, emphasizing edge-to-edge light return,
ladies and gentlemen, here are 2 fine examples of craftsmanship in cutting square princess-cuts:''

Live long,

Paul Slegers
Infinity Diamonds
www.CraftedByInfinity.com

P.S. I am downloading the file he labeled ASET2 first as the other one is too big and I need to go resize it.

Very nice indeed gentlemen. I have had my chin jarred. But I need another decent blow to lay me out flat.

The old subtract the tabe from the crown upper cut would probably do it. (You know the one where you send me a link or a Gem Adviser file, or a diamCalc Cut Quality screen shot)

 

[diagem]

Date: 12/19/2007 12:52:33 PM
Author: Wink
And finally, file reduction phone calls, and now file renaming...

I present to you ASET_1.

You are welcome Paul!

Looks like the pavilion angles on this beauty is based on a shallower (than usually) angle???

 

[WinkHPD]

Date: 12/19/2007 2:12:01 PM
Author: DiaGem

Date: 12/19/2007 12:52:33 PM
Author: Wink
And finally, file reduction phone calls, and now file renaming...

I present to you ASET_1.

You are welcome Paul!

Looks like the pavilion angles on this beauty is based on a shallower (than usually) angle???

Hmmm,

I doubt it, although you would have to ask the master as I know not which stones these are, only that knowing who they are from that they are either AGS 0''s or 1''s due to some minor defect in polish. He has long since gone home for the evening as it is after 9:30 in his part of the world.

I went to his site and just grabbed the crown and pavilion angles of the top three princess cuts in the search for princess catagory. I did not note the size or quality or cut grade of each stone, only grabbed the angles and looked at the aset. I can tell you honestly that the stone with the deepest pavilion angle had the most stunning ASET of the group.

Stone 1. PA 42.2 CA 32.2

Stone 2. PA 42.1 CA 32.6

Stone 3. PA 42.7 CA 33.2

All had ASET pictures similar to the two posted above. and stone number 3 was better than the two posted above.

LOL, just went back to look and it is an AGS 1 for excellent finish deduction. (Still hard for me to wrap my mind around excellent being a deduction.)

I also grabbed and attached the ASET image herein presented.

Wink

 

[WinkHPD]

Date: 12/19/2007 1:58:06 PM
Author: Garry H (Cut Nut)

Very nice indeed gentlemen. I have had my chin jarred. But I need another decent blow to lay me out flat.

The old subtract the tabe from the crown upper cut would probably do it. (You know the one where you send me a link or a Gem Adviser file, or a diamCalc Cut Quality screen shot)

Please translate subtract the tabe from the crown for me, I am lost. As for the files, we shall have to depend on Paul, I know not even which two stones these are... Just that every one of his that I have seen have very similar ASET images.

I suspect Paul will be happy to send you links and files in the morning.

(His morning)

Wink

 

[strmrdr]

Date: 12/19/2007 12:15:49 AM
Author: DiamondExpert
...the 2nd one ''on the rocks'' - same stones.

How long would a princess last before getting broke set like that in a ring?
The corners are in the most vulnerable positions.

 

[WinkHPD]

Date: 12/19/2007 10:56:34 PM
Author: strmrdr

Date: 12/19/2007 12:15:49 AM

Author: DiamondExpert

...the 2nd one ''on the rocks'' - same stones.

How long would a princess last before getting broke set like that in a ring?

The corners are in the most vulnerable positions.

Set properly with v-caps there is no reason the stone would not last a long time. We have done it many times and not one of the stones has returned to us for a chipped corner. The only two chipped corners in my career so far have been in standard set rings.

That is a non mathematically insignificant sampling, it is just my experience over 30 years in the business. Also it should be noted that I have set MANY MANY more in the standard position.

Wink

 

[DiamondExpert]

Ya, and remember this stone in the pic, and all the others from this cutter, are camphered (have a minute facet across the sharp corner) which is allowed by AGS prior to grading - so the likelyhood at and after setting of chipping is less.

 

[Paul-Antwerp]

And in the second round, going for the upper-cut.

You can find the Sarin-files in these links, Garry: =232&src=loupe:2o8h065d]link1 and =253&src=loupe:2o8h065d]link2

Although the Sarin has its limitations, and misses some facets, I think that you can work with this.

If you wish, I can also give more background-info on this ''Tolkowsky of princess-cuts''. But that might only be after the holidays, since I am going into non-internet-mode tomorrow for about 10 days.

Live long,

 

[diagem]

Date: 12/20/2007 2:52:57 AM
Author: Paul-Antwerp
And in the second round, going for the upper-cut.

You can find the Sarin-files in these links, Garry: =232&src=loupe:2o8h065d]link1 and =253&src=loupe:2o8h065d]link2

Although the Sarin has its limitations, and misses some facets, I think that you can work with this.

If you wish, I can also give more background-info on this 'Tolkowsky of princess-cuts'. But that might only be after the holidays, since I am going into non-internet-mode tomorrow for about 10 days.

Live long,

Sarin link #2: (I cant seem to be able to open link #1)

A 1.40 carat Princess is measured by Sarin as a 7.25mm. diameter?
Also..., is the CA and PA #'s based on an average of P1 and P2---C1 and C2?

Even though..., I dont understand the CA #'s of 20.3 degrees?? Are they real?

 

[Garry H (Cut Nut)]

B@@M

Date: 12/20/2007 2:52:57 AM
Author: Paul-Antwerp
And in the second round, going for the upper-cut.

You can find the Sarin-files in these links, Garry: =232&src=loupe:2o8h065d]link1 and =253&src=loupe:2o8h065d]link2

Although the Sarin has its limitations, and misses some facets, I think that you can work with this.

If you wish, I can also give more background-info on this ''Tolkowsky of princess-cuts''. But that might only be after the holidays, since I am going into non-internet-mode tomorrow for about 10 days.

Live long,

the Gem Adviser / DiamCalc light return for this stone is very good (for a princess cut)

Look at the data for table as compared to the whole crown.

Note the light return for the table region is 77% and 90% of that of a Tolkowsky round.
Note the light return for the whole crown is 66% and 82% of the light return for a Tolkowsky round.

So this means the outer crown facets are letting the side down relative to the table.
Say the table was exactly 50% of the area (and weighting), then the crown facets only result would be 55% and 74% respectively.

This shows that even on such a nice princess cut, there is relatively less light return at the edges compared to table region. this makes sense because we always see more red in the center of a well cut princess cut.

 

[Paul-Antwerp]

In these percentages, are you taking into account that in a round, the contrast-pattern is part of the light return, while in a princess-cut the contrast-pattern comes more from leakage?