Scared of the 2005 AGS fancy charts

[lovesquares]

How much of a difference do you think there will be between the 2005 AGS princess parameters and those created by AGA (which I feel have been incredibly helpful to all of us who love fancies).

Is the AGS expected to release parameters for cusions and asschers?

 

[strmrdr]

If they arent close to the aga numbers Id be more suspicious of the ags numbers than the aga ones.

 

[Garry H (Cut Nut)]

(Only DiamCalc users will fully understand this post)

The new AGS princess charts are guidelines for manufacturers. AGS modeled diamonds in DiamCalc with complex H1, H2, H3 relationships. They modeled hundreds of thousands of square princesses to get high and low values. Also, the charts are only for princess cuts with 2 rows of ''chevron'' facets on the pavilion. They are currently modeling 3 and 4 chevron row variations. In their new system, all of the facets will matter because they will use a very accourate ray trace a 3D scan of the stone. If a manufacturer cuts normally, without indexing any facets, the guidelines should be very accurate.

So if there are some unusual combinations of proportions that are outside AGA guidelines - it may not be a surprise.

BTW what they have done is similar to the basis of HCA (for which I have recieved endless criticsm) - but far more complex because princess have more crown and pavilion angles.

 

[Rhino]

On the new nomenclature it does state that there are other factors that will ultimately determine the grade but knowledge of those 2 sets of crown angles and 2 sets of pavilion angles are cursory information that will be required.

Insofar as the new AGS scales compare to the AGA scales, there is a marked difference as AGS is getting into a knowledge of more details. Dave''s scale (which I respect btw) only covers crown height and not pavilion depth which to a point disregards the importance of the crown/pavilion relationship. Also if you''ve read any details on the HCA you know that angles are always more important to know than percentages.

One project we completed today is a customized Sarin report featuring the exact angles AGS is looking for to be able to properly grade princess cuts.

 

[Garry H (Cut Nut)]

Would you mind sending me one of your new Sarin reports please Rhino?