PLEASE help, my head is spinning

candide · Sep 3, 2003

Hi-

I am a scientist (brain not gems), so I am a data person. Now my head is spinning a bit because of all of the cut grading systems. I am getting disparate answers from HCA, AGA, and AGS on a specific stone. I am getting close to buying so please help.

2.84 H VS1
9.01*9.07*5.68 mm
Depth 62.8 %
Table 56.7%
Crown: 35.5 degrees 15.3%
Pavil: 41.3 degrees 43.6%
Culet: 0.8%
Girdle medium to sl. thick
VG/VG

By AGS this is essentially 1 on Pavilion depth, 0 for crown angle, 0 for table, 0 on girdle thickness, 0 on culet ..... so pretty good

By AGA Atlas'' system puts this at 2A (table 1A, crown angle 2A, Crown height 1A, pavillion 2A, girdle 1B, depth 1B..... pretty good

But by HCA this is one of the worst stones I have checked at 4.4 (only if price is the main concern)...

Please help what gives? I guess I am starting to split hairs maybe..... Or am I seeing further down the rabbit hole

?

Thanks for any input on this stone.
Jon

candide · Sep 3, 2003

And to boot, GIA would put this Pavilion at Class 3/ Fair, while AGS would be good with it. Whoa... please help

Richard Sherwood · Sep 3, 2003

Here's the reason the HCA scale is dragged down. The crown and pavilion angle (35.5/41.3) is what we call a "steep & deep" combination, which usually produces a moderate ring of light leakage just inside the table.

With the "numbers" system, the diamond technically ranks pretty good. With the newer optical grading system of the HCA and DiamCalc, the light performance ranks more like "good", as opposed to "very good" or "excellent".

Bear in mind though that "good" ranks better than "fair" or "poor", of which there are a lot of diamonds out there that women are admiring and enjoying everyday.

Both the HCA and DiamCalc are harsh critics, meant for cut geeks who are looking for optimal performance in the top 2% of diamonds cut. This stone in all likelihood would be pretty and enjoyable, with only cut geeks noticing a moderate amount of leakage inside the table.

If the stone fits your needs, have it shipped in to check it out. If it looks great to you, go for it. If it doesn't perform as well as you would like it to, you're only out the return shipping charge.

The following POSSIBLE simulated IdealScope image shows the area of light leakage inside the table as a white ring. The photoreal image following that shows it as a dark area just inside the table. In real life I find this not be as noticeable as the photoreal image usually indicates.