Crown Angles are greater than 35

[mdancel]

I was looking at a GIA certificate on a diamond. In the comments section it stated, "Crown angles are greater than 35 degrees". The sales person was trying to explain to me that this was a positive thing. Is this angle really a good thing or a bad thing.

Here is the rest of the info on the cert:

Round 1 ct.
Measturements 6.33 x 6.35 x 4.01
Depth 63.2%
Table 57%
Girdle - Medium to Sl Thick, Faceted
Culet None
Polish - Excellent
Symmetry - Excellent
Si
I
Flouresence - Faint
Comments:
Additional clouds are not shown
Crown angles are greater than 35 degrees.
$3950

Any insights to the comment "greater than 35 degrees"? How about the price?

 

[diagem]

According to the info. of the cert. it seems to be a good diamond, a little small in diameter than an ideal made stone, but dont let the 35 degree comment throw you off!!!!! and i dont think that 1/20th. of a milimeter will make such a difference in the look.

An ideal made crown is on the average 34 degrees. so its NOT A BAD THING..., Me personaly like diamonds with steeper crown angles, but its a matter of taste,

But again according to the cert. you should have a beautifull diamond in you hands.

About the price, i am trying to make it a habit of not commenting unless its a number that would show an act of great unfairness.

 

[Garry H (Cut Nut)]

Contrary to DG''s advice, I would pass on this stone.

I too like many diamonds with crown angles above 35 degrees.

But this one will also have a pavilion angle above 41 degree''s, and that is really bad.

 

[diagem]

Sorry Garry, I know you dont like most of my oppinions, but to call a diamond with 35 degree crown and 41 degree pavillion, with ex sym. AND ex Pol. a bad diamond, thats throwing a consumer the worst posible advice.....

I personaly know plenty of diamonds with much worse descriptions that are very, i repeat VERy beautifull Diamonds....

Please give some credit to this industrie.

According to your strong believes, this diamond may not be an ideal make, but I still am not sure it wont get ideal makes with some serious gemologists.

 

[mdancel]

Gary or anyone else,

How did you get the 41 degree Pavillion Angle from the numbers I gave above?

Thanks,
mdancel

 

[diagem]

There are formulas.......

 

[valeria101]

Date: 10/30/2004 11:20:32 AM
Author: mdancel
Gary or anyone else,

How did you get the 41 degree Pavillion Angle from the numbers I gave above?

Got table, girdle,depth and an estimate crown angle (something above 35, as GIA says), from this you can work out a minimum pav. angle via basic trigonometry. I think this is what they are talking about... The result of steep crown & pavilion may be a diamond with a dark patch under the table (= "nail head"). Chances are this is the case and I can only assume that it is easier for you to look for a stone that has more promissing measurements. You could also try to compare the diamond with an ideal and see what the difference is (after all, numbers are only an approximation of the actual thing).

It does not take looking hard to spot this 'nail head' look. Knowing what to look for and not too bright lighting (daylight, instead of strong shop lights) should help.

This may sound like splitting hairs already, but... the more you get to look at diamonds the more obvious these things get.

Just my o.2, of course.

 

[Garry H (Cut Nut)]

DiaGem this diamond would fail the GIA''s new "pattern" test because of the table leakage darkness Ana refers to.
It will not be an AGS 0 next year - because it wil perform like the stone on the AGS ideal section in the tutorial (which we are about to upgrade).

Therefore the gemologists who like it now will change their opinion (you heard it first on Pricescope )

The easiest way for a professional to estimate angle ranges is to simply build the diamond from the #''s with DiamCalc which you can read about or buy for $280 under Tools at the top bar.

It can help limit the possabilities of what is shown in the 60:60 part of the tutorial - having the crown angle above 35 helped me narrow the possiible range of pavilion angles. It is a stone that could be good, it would not be really bad, but can not possibly be excellent - so why consider it?

 

[diagem]

First, i am glad we agree on something finaly, you admit to calling the above mentioned diamond "realy bad" a mistake.

Secondly, you should now by now that i am not on this site to purchase any "tools"!!

I really think that gemologist that change their minds sooooo fast, are becoming marketing tools, and loose the real reason to become gemologists.....

 

[CDNBOY]

Wat is gonna be considered AGS0 next year?

Is there a new set of Crown angels and pavillion angles we should know about?

 

[Garry H (Cut Nut)]

Do a search - there are recent threads with some published results.