Why Princess Table and Depth % data is useless

[Rhino]

Date: 5/8/2005 2:35

6 PM
Author: Paul-Antwerp

Date: 5/8/2005 1:29:59 PM
Author: oldminer
If finer performing princess cuts are possible to cut with reasonable depth, then ones with a 78% depth are going to look quite small for their weight.  I don''t think it is fair to call such a stone ''Ideal'' without qualifying that its Light Performance is Ideal and its Cut Quality is less than optimal.  Any consumer or retailer with common sense would prefer a larger lookiong, equally high performance diamond.......at least, I think they would.  Does anyone disagree or agree with this argument?

I''d love to hear other people comment.

I am sorry, David, but it seems to be only me who comes back to this subject.

The fact is that, in a princess, there is no inverse connection between depth and spread. It is fairly easy to cut two stones with the same diameter and the same weight, while one has a depth of 65% and the other one a depth of 75%. This is directly opposite to your point that a stone with 78% depth will look quite small.

To once again put it in the words of R.E.M.: ''It is the end of the world as we know it''. Please wake up, and look with other eyes. I know that I had to do it, and it is definitely enlightening.

One reason why we should pursue this conversation. Excellent thread. I''ll see if I have some *live* examples I can post that demonstrate the point.

 

[researcher]

Thank you, thank you, thank you!!! These posts have very much clarified everything for me (and hopefully several other PSers). Rhino and Paul, your posts especially helped me to understand princess cuts a lot better

I really appreciate the fact that you expressed your opinions in such a way that even a novice like me could easily follow

I finally get it!!!

 

[Paul-Antwerp]

Hey Rhino,

While you were on vacation, you have missed this thread: princess-depth

It is essential that you catch up on this.

Live long,

 

[Rhino]

Date: 5/8/2005 3:54:55 PM
Author: Garry H (Cut Nut)

Date: 5/8/2005 3:28:37 PM
Author: Rhino

Date: 5/7/2005 8:15:56 PM
Author: Garry H (Cut Nut)
Exactly Johan, and that''s why I have been saying for years that the monir facets on rounds only play a minor effect - it is to do with the way they are ''tied'' together.

Hi Gary!

Just curious.  If 2 rounds have the same general proportions (lets say 34.5/40.8/56) and one diamond has lower girdles that are 70% length and another has 80% length, in your opinion you consider this to be a minor visual difference between the 2?

Hi Rhino,
There is no weight gain advantage to the cutter to make a stone with a 70% or a 90% lower girdle facet, so therefore the argument is mute - how many such stones do we see with really bad minor facet structures - answer - very very few - reason - cutters are not that silly.

Do we see many minor facet screwed up princess? Boy do we ever? Does the cutter do it for yeild and monetary gain? - you betcha!

No arguement on the princess cuts but the point about weight gain advantage concerning lower girdles does not address my point of how much lower girdles impact diamond appearance. I know of cutting houses who cut stones to ideal proportions who consistently put out stones witih lower girdles around the 68-70% length, I also know of cutting houses who cut their goods to 74-75% on a consistent basis others around 80%, then some factories where they''re all over the place. So my question doesn''t pertain to weight gain advantage. I''m inquiring for your opinion about if you think there is a minor or major difference in appearance in 2 ideal cut diamonds ... one having 70% lower girdles vs one have 80% lower girdles. I have a definite opinion about this but was curious if you felt the difference in appearance was only minor between 2 such stones. Another way of wording the question ... Do you think that you or perhaps a consumer would be able to *see the difference* between the following 2 stones?

 

[Rhino]

Date: 5/8/2005 4:43:29 PM
Author: Paul-Antwerp
Hey Rhino,

While you were on vacation, you have missed this thread: princess-depth

It is essential that you catch up on this.

Live long,

Thanks. I''ll read this at my earliest convenience Paul.

Researcher... thanks from Paul and I for your kind words. One of the greatest challenges we face (on the forum anyhow) is being to put all this into language that good ol regular folks like you (and others not in the trade) can understand.

 

[Garry H (Cut Nut)]

Date: 5/8/2005 8:27:26 PM
Author: Rhino

No arguement on the princess cuts but the point about weight gain advantage concerning lower girdles does not address my point of how much lower girdles impact diamond appearance. I know of cutting houses who cut stones to ideal proportions who consistently put out stones witih lower girdles around the 68-70% length, I also know of cutting houses who cut their goods to 74-75% on a consistent basis others around 80%, then some factories where they''re all over the place. So my question doesn''t pertain to weight gain advantage. I''m inquiring for your opinion about if you think there is a minor or major difference in appearance in 2 ideal cut diamonds ... one having 70% lower girdles vs one have 80% lower girdles. I have a definite opinion about this but was curious if you felt the difference in appearance was only minor between 2 such stones. Another way of wording the question ... Do you think that you or perhaps a consumer would be able to *see the difference* between the following 2 stones?

Rhino they either make those stones because there are people who like them (aka old cut lovers) or they are ignorant - but either way they are not a train smash so long as the main proportions are good (which may well not be the case? - so ignorance rules?). Now I know you have a litle market niche specializing in supa dupa ideals - but ya gotta remeber my campaign is simply to rule out lousy looking diamonds. The stone with the fat arrows and short LG''s would find a happy buyer - it is not ''lousy'', and if you had 70% LG''s with 65% plus tables (common in te Mauls), then 70% is better than 80% anyhow''s

The princess are bad bad bad because they are light return train smashes, and the bad practice has been done for many years thereby becoming the norm.

We gotta change it boys and girls - because we are crusaders.

 

[Garry H (Cut Nut)]

Date: 5/8/2005 3:47:25 PM
Author: Paul-Antwerp
Just out of curiosity, I quickly calculated the lowest possible total depth for different table sizes, which can still get an AGS-0 cut-grade. These figures are absolute minima, and with this, you are working really at the edge of the chart.

For a table size of 55%, you need at least 69.66% depth
For a table size of 60%, you need at least 69.50% depth
For a table size of 65%, you need at least 69.50% depth
For a table size of 70%, you need at least 70.00% depth
For a table size of 75%, you need at least 73.33% depth
For a table size of 80%, you need at least 72.16% depth

For each table size with this depth, you have to cut with one specific set of 2 pavilion angles and 2 crown angles. If not, no go. In order to have some more leeway to realistically cut for AGS-0, you need at least 4% more depth than indicated above.

Live long,

Well done Paul- it was on my list of stuff - we can do more of this - what girdle thickness did you use?
Did you take spread into account?
Why not do upper limits based on the 25% pread factor too?

 

[Garry H (Cut Nut)]

Hmmmm, we have just done a little work on the depth to table sizes and it is (as i thought), not at all simpe and straight forward.

Using the AGS charts one finds that all the ideas being discussed here are about best table sizes to depth %''s etc are flawed.

I will check the data before making more comments.

 

[laughinggravy]

Just a consumer using her eyes, but Paul''s Princesses are a completely different beast. It''s positively weird... you look and you realise it''s a Princess cut, but it looks nothing like other Princesses.
Abi