Pavilion and Crown

shelleydog · Apr 15, 2008

If the pavilion is a higher number (41.2) should the crown also be higher (35) or should the crown be a smaller number (33) if the pavilion is higher. Sorry, I''m confused. I have been reading alot here.

Splinter · Apr 15, 2008

I'm not 100% sure on this. It's hard to tell without being an expert in cutting diamonds. However, I ran a few scenarios through the Cut Advisor. The lower the score, the better the cut. Using 41.2 as the pavilion angle:

Crown Angle: 33
Score: 1.8

Crown Angle: 34
Score: 2.8

Crown Angle: 35
Score: 3.4

So based on this (very unscientific) experiment, it would appear a lower crown angle will balance a higher pavilion angle.

LuckiestGuyonEarth · Apr 15, 2008

Splinter has it, in general you want them to be opposite if they are out of ideal, that is just a generalization and I think it depends, but if one is higher than ideal you want the other measurement lower and vice versa.

Ben

Lorelei · Apr 15, 2008

Date: 4/14/2008 9:51:21 PM
Author:shelleydog
If the pavilion is a higher number (41.2) should the crown also be higher (35) or should the crown be a smaller number (33) if the pavilion is higher. Sorry, I'm confused. I have been reading alot here.

You want the crown and pavilion angles to complement, so if you have a steeper pavilion angle, generally a shallower crown may be the best fit, but it is very hard to be specific here, as it is quite a complex subject with many possible good and bad variations. There is less flexibility with the pavilion angle than with the crown angle generally speaking, and most importantly, each diamond needs evaluation on it's own proportions. The pavilion angle noted above is considered to be steep.

Garry H (Cut Nut) · Apr 15, 2008

http://diamonds.pricescope.com/crn_pav.asp explains the principal.

say 40.75 P and 34.5 C is ideal , then for every 1 degree + pavilion angle subtract 5 degrees from the crown angle.

There is a tool based on Tolkosky here http://www.folds.net/diamond/software_help.html that was developed by one of our occasional but regular mathematician posters, Jasper Paulsen.

shelleydog · Apr 15, 2008

Thank you for the replies. I''m having fun playing with the tool Garry posted. I never realized how complex diamonds are.

Garry H (Cut Nut) · Apr 15, 2008

Date: 4/15/2008 8:22:45 AM
Author: shelleydog
Thank you for the replies. I''m having fun playing with the tool Garry posted. I never realized how complex diamonds are.

Diamonds are simple

we are complex

Sparkles4Luv · Apr 15, 2008

Garry H- I like your comment. It is very true. I think as humans we like to make things complicated and thus rationalizing why we make good/bad decisions. I''m extrememly happy that websites like Pricescope exist because it allows people to make educated decisions about things like Diamonds. Otherwise we get stuck trusting what a sales associate tells us at local store.

dmus · Apr 15, 2008

Date: 4/15/2008 7:13:30 AM
Author: Garry H (Cut Nut)
http://diamonds.pricescope.com/crn_pav.asp explains the principal.

say 40.75 P and 34.5 C is ideal , then for every 1 degree + pavilion angle subtract 5 degrees from the crown angle.

There is a tool based on Tolkosky here http://www.folds.net/diamond/software_help.html that was developed by one of our occasional but regular mathematician posters, Jasper Paulsen.

I''m a little condused. If p is 41.75 which is one degree higher the c should be 29.5? Similarily 40.85 p to 34.0 c by your calc. Is that right? Thanks.

Garry H (Cut Nut) · Apr 15, 2008

Date: 4/15/2008 2:55:55 PM
Author: dmus

Date: 4/15/2008 7:13:30 AM
Author: Garry H (Cut Nut)
http://diamonds.pricescope.com/crn_pav.asp explains the principal.

say 40.75 P and 34.5 C is ideal , then for every 1 degree + pavilion angle subtract 5 degrees from the crown angle.

There is a tool based on Tolkosky here http://www.folds.net/diamond/software_help.html that was developed by one of our occasional but regular mathematician posters, Jasper Paulsen.

Click to expand...

I''m a little condused. If p is 41.75 which is one degree higher the c should be 29.5? Similarily 40.85 p to 34.0 c by your calc. Is that right? Thanks.

That''s right

dmus · Apr 15, 2008

Thanks Gary.

Just one more question from a very inquisitive student. So I could have an excellent light performing diamond at 41.75 P and 29.5 C even though these measurements would probably make it less than desirable cut by AGS or GIA standards? I also assume these figures would yield a rather deep diamond. Is that why I can see GOG or WF advertizing diamonds that are H&A and great light perfomers supposedly but by the numbers look very much less than ideal to me? The answer to this would be very enlightening. Thanks.

strmrdr · Apr 15, 2008

ummmm it is not that simple....
That is true only if you want too make the same compromises that a tolk makes.
There are a lot of other great combos out there that place the compromise point in different places too produce high performance diamonds.

On of my favorites is 34/41 Brian likes 34.8/40.8 Paul likes a slightly different combo for his brand with proper table, minor facets and optical symmetry they are all kicken diamonds.

But in general the steeper the pavilion the shallower the crown and steeper the crown the shallower the pavilion but that doesn''t always hold true.
35/41 being one such combo that has a lot of fans.
The table size makes a large difference in what is a suitable angle combination also.
The HCA makes this easy.

This is talking RB only, when it comes too step cuts the RB rules go out the window.

dmus · Apr 15, 2008

Thanks strmrdr. Why couldn''t it be simple.

strmrdr · Apr 15, 2008

41.75 29.5 60%t 80% lgf% 55% stars, AGS3 potential by the cutting charts for the c/p combo.

strmrdr · Apr 15, 2008

tolk is a 1 on this scale...

strmrdr · Apr 15, 2008

Likely why AGS kicked it down...
Again tolk is a 1

strmrdr · Apr 15, 2008

In pictures why AGS kicked it down...

strmrdr · Apr 15, 2008

Modern tolk, notice the amount and the distribution of blue compared too the above.
So when it comes too raw light return the math is valid it dont tell the whole story....

strmrdr · Apr 15, 2008

It took me a while too figure this out I would create what looked too me like a kicken virtual diamond and the AGS software would kick it down too 3 or even 5.
Frustrating LOL
But I learned....

dmus · Apr 15, 2008

Date: 4/15/2008 4:39:22 PM
Author: strmrdr
tolk is a 1 on this scale...

I probably over stated the student part. I don''t know how to interpret the charts here but the gist I guess is that with the Pav 41.75 and crown 29.5 the star facet, table and other dimensions must now be considered.

I suspect when I see complimentary P and C angles I''ll just come back here for additional eval or rely on idealscopes and ASETs to do final assessment of a diamond.

strmrdr · Apr 15, 2008

Date: 4/15/2008 5:03:00 PM
Author: dmus

Date: 4/15/2008 4:39:22 PM
Author: strmrdr
tolk is a 1 on this scale...

Click to expand...

I probably over stated the student part. I don''t know how to interpret the charts here but the gist I guess is that with the Pav 41.75 and crown 29.5 the star facet, table and other dimensions must now be considered.

I suspect when I see complimentary P and C angles I''ll just come back here for additional eval or rely on idealscopes and ASETs to do final assessment of a diamond.

With any combo all the facets must be considered.
Aset and IS make it easier, look for the proper look, check it against being too shallow pavilion for a ring, check for a lgf% mismatch, Done...
Or just post the numbers and IS/ASET here for an opinion :}

jady_cat · Apr 15, 2008

How about 41.1 P / 33.9 C/table 59 ? good combination?

strmrdr · Apr 15, 2008

Date: 4/15/2008 5:41:39 PM
Author: jady_cat
How about 41.1 P / 33.9 C/table 59 ? good combination?

potentual AGS0 depending on the other facets so yes it can be a good combo.
Its a little different than the more tolk like diamonds that are considered to be the best of the best here but can be a pretty diamond if everything is cut right.
An IS or ASET image would tell the story.

jady_cat · Apr 15, 2008

strmrdr:

Please say something about these 2 stones.Many thanks ! I especially want to know more about the No.2 stone.

No.1 is better than No.2? or they are just almost the same.

Sorry I don''t have IS or ASET image.

Here are 2 stones.

No.1 VVS2 F color (AGS cut: ideal 0)

HCA score is 1.8

Pavilion angle 40.7

crown angle 35.4

Cut: ideal

Depth: 62.0%
Table: 56.4%

Polish: Ideal

Symmetry: Ideal

Girdle: Thin to medium

Culet: None

Fluorescence: Neglible

Measurements: 8.17*8.21*5.08

No.2
1.67 ct (Tiffany''s ex/ex/ex)

HCA score is 2.5

VVS2 F

Table 59%

Crown angle 33.9

Crown height:14.1%

Pavillion angle 41.1

Pavillion depth 43.5%

Total depth 60.8%

star length percentage:55%

lower half length percentage 80%

Girdle :medium-slightly thick
Girdle finish:faceted

Measurements:7.67/7.69/4.67 mm

strmrdr · Apr 15, 2008

I would like #1 better if they were the same size but since #1 is bigger it gets a double win.

The 2nd isnt likely an ugly diamond by any means but not the best either.

they would have totally different looks.

What does the pricing look like?

jady_cat · Apr 15, 2008

The link for the No.1 $36,620
http://www.jamesallen.com/diamonds/F-VVS2-Ideal-Cut-Round-Diamond-1121281.asp?b=16&a=12&c=77&cid=131

No.2 is actually not a loose stone.A tiffany e ring with Micro pave halo setting $41500

I already purchased it and I want to return it now.

MikeRato1 · Apr 15, 2008

what would you guys say about the 1st stone if all the measurments were the same except having a larger table @ 58%?

strmrdr · Apr 15, 2008

Date: 4/15/2008 7:48:46 PM
Author: MikeRato1
what would you guys say about the 1st stone if all the measurments were the same except having a larger table @ 58%?

35.4/40.7 58 is ok sometimes, the table is right on the border of too big for the combo.
The lgf% and stars would have too be right as its borderline ags0/ags1 and the minor facets can move it one way or the other.
If I recall right not long ago someone here bought a 35.5/40.6/58 80% lgf and loved it.
Its a bit outside of the norm for here.

strmrdr · Apr 15, 2008

Date: 4/15/2008 7:19:58 PM
Author: jady_cat
The link for the No.1 $36,620
http://www.jamesallen.com/diamonds/F-VVS2-Ideal-Cut-Round-Diamond-1121281.asp?b=16&a=12&c=77&cid=131

No.2 is actually not a loose stone.A tiffany e ring with Micro pave halo setting $41500

I already purchased it and I want to return it now.

The JA diamond is real nice.
Id get an IS image too confirm everything but it looks good too me.

Whats wrong with the current one? Dont love it?

jady_cat · Apr 15, 2008

The setting of the Tiffany ring is really nice,but the price tag is...

Plus the ring looks lack of fire.

I asked opinions days ago. They all suggested me to return it. What do you think? Worth the price? ($41500)

https://www.pricescope.com/community/threads/pls-help-me-make-a-decision-urgent.83037/

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