Why is this Stone only a VG Cut per GIA

[mrb09]

Hi,

Found another stone that I like the numbers on. Wish I had an AGS report, but it's GIA. Wondering why this has been graded as a VG cut when it appears to be a really nice FIC stone per it's dimensions. Can I please have your opinions? Thank you!

http://www.b2cjewels.com/Images//Certificate//4189562.pdf

 

[yssie]

Thick girdle max
GIA proportions chart indicates VG for c/p at 55t
http://www.diamondcut.gia.edu/pdfs/booklet_cut_estimation_tables_highres.pdf
I would recommend seeing it before setting - avg pav is quite shallow esp since pav is rounded up

 

[Evilsports]

I'm far far from being anything more than a consumer, but that was my take on it as well.

The shallow pavilion, coupled with the thick girdle and steep(ish) crown angle, would be my guess. It seems to me to be a bit top heavy, as compared to most of the stones I've been looking at.

 

[Evilsports]

Hi,

Found another stone that I like the numbers on. Wish I had an AGS report, but it's GIA. Wondering why this has been graded as a VG cut when it appears to be a really nice FIC stone per it's dimensions. Can I please have your opinions? Thank you!

http://www.b2cjewels.com/Images//Certificate//4189562.pdf

If it's any help, I've found this tool to be helpful to me, at least in determining what might be strong or "weak" aspects to a specific stone.

http://datlas.com/do-it-yourself-aganaja-cut-class-grader/

 

[Karl_K]

40.2 pavilion is too shallow for a ring even with a 36 crown.

 

[mrb09]

awesome, missed the girdle. thanks guys. scratch that stone off the list.

 

[mrb09]

i don't want to clog up the board with all new threads, so I'll go here. what do you think of this stone? Angles seem complimentary.

http://www.jamesallen.com/loose-diamonds/round-cut/1.78-carat-h-color-vs2-clarity-excellent-cut-sku-270650

 

[MissGotRocks]

Should be a nice stone! Just make sure it is eyeclean enough for you!

 

[mrb09]

i noticed that under the 400x mag i could see the crystals, but I can't imagine them being visible in person, being a VS2…no way to tell without ordering it though I suppose.

 

[JulieN]

#2 has rather skinny arrows. It does seem to be giving off a light show, though. You get to pick 3 for review.

 

[diamondseeker2006]

Definitely worth getting idealscope images of #2. Skip VG cut.

 

[WinkHPD]

40.2 pavilion is too shallow for a ring even with a 36 crown.

To me this type of cut is why I think the GIA system that allows 80% of all diamonds cut by the major cutting houses to achieve either an Excellent or Very Good rating is too lenient. Hard to know without seeing it, but I suspect that an idealscope or an ASET of this image will show it leaking like a sieve.

I am traveling and can not access some of my toys, but I would love to see an ASET of this diamond as well as knowing what the light performance grade for this diamond would be with AGS.

Anyone want to run those numbers?

Wink

 

[John P]

Hey Wink,

I'm pretty sure you must have misread 40.2 as 42.0? That would indeed leak and draw light from low angles...and is an example of a steep-deep combo which is GIA VG, but predicted AGS 6-9, depending on specifics.

The 40.2 36.0 with 55 table cited here is robust by the basic numbers - but subject to significant obstruction. So it would need to be admired from afar. Maybe good for a pendant, or in an earring for an NBA player?