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Are Excellent Cuts really the same from anywhere?

phaketrash

Rough_Rock
Joined
May 23, 2011
Messages
12
I often hear this so I really wanted to get some confirmation (let's say dealing with GIA only). Are excellent cuts essentially the same regardless of where they come from? Whether it be online Bluenile or Jareds vs. DeBeers or Harry Winston? If they have that Excellent cut description, are they all roughly the same (i.e. you're just entirely paying extra for the brand? i know on some level some of the extra $$$ is for the brand, but all of it?)

Thanks!
 

phaketrash

Rough_Rock
Joined
May 23, 2011
Messages
12
thanks for the article link -- it was helpful, but im still a bit confused

1) when the article says different "labs" will all give it the same grade (ex: Excellent), does it mean each individual jeweler's lab (debeers vs. Harry Winston) or GIA vs. some other lab like EGL (sp?)?

2) the article stopped just short of something really profound -- how do you tell based on measurements, etc. which diamonds are better than other ones in the same cut grade?! lol
 

slg47

Ideal_Rock
Joined
Apr 4, 2010
Messages
9,667
these are all GIA Ex.

you can use the HCA tool to find good candidates

pricescope.com/tools/hca
 

thbmok

Brilliant_Rock
Joined
Jul 30, 2010
Messages
891
phaketrash|1306210280|2928856 said:
1) when the article says different "labs" will all give it the same grade (ex: Excellent), does it mean each individual jeweler's lab (debeers vs. Harry Winston) or GIA vs. some other lab like EGL (sp?)?

2) the article stopped just short of something really profound -- how do you tell based on measurements, etc. which diamonds are better than other ones in the same cut grade?! lol
The article primarily shows the variances within the top cut grades of GIA/AGS. Have another look at section D. Expert Details. All the diamonds shown have GIA Excellent cut grade, with less than half of them attaining AGS Ideal cut grade. All the measurements and images are also listed for each diamond. It is debatable whether certain diamonds are better than others within the same cut grade, but I think it should be fairly easy to come to your own conclusions over what your own preferences are.
 

dreamer_dachsie

Super_Ideal_Rock
Joined
Dec 16, 2007
Messages
24,364
All diamonds graded by GIA and having an excellent cut grade are essentially the same no matter who is selling them. The brand name of Harry Winston etc does NOT change one little thing, it is still a GIA Ex for cut. So yes, you pay a LOT for brand name.

Within the GIA Ex cut grade there is some variation in how perfectly, ideally proportioned the stones are, as the article slg linked suggests. So it is worth it for someone very interested in top cut to weed through GIA Ex cut stones to pick out certain stones that meet even tighted cut criteria. BUT to my knowledge, Harry Winston et al. do NOT do such weeding (though they may says something about "hand selecting" or such, I doubt they can provide criteria for that selection process beyone GIA Ex and certain color clarity parameters). And so, once again, the brand is not buying you much over looking for a GIA Ex cut from elsewhere.
 

denverappraiser

Ideal_Rock
Trade
Joined
Jul 21, 2004
Messages
8,840
There is considerable variation within the category of GIA-excellent and there's a bit of debate over the topic of what is 'best' but where they come from has nothing at all to do with it.
 

phaketrash

Rough_Rock
Joined
May 23, 2011
Messages
12
Dreamer_D|1306254855|2929166 said:
All diamonds graded by GIA and having an excellent cut grade are essentially the same no matter who is selling them. The brand name of Harry Winston etc does NOT change one little thing, it is still a GIA Ex for cut. So yes, you pay a LOT for brand name.

Within the GIA Ex cut grade there is some variation in how perfectly, ideally proportioned the stones are, as the article slg linked suggests. So it is worth it for someone very interested in top cut to weed through GIA Ex cut stones to pick out certain stones that meet even tighted cut criteria. BUT to my knowledge, Harry Winston et al. do NOT do such weeding (though they may says something about "hand selecting" or such, I doubt they can provide criteria for that selection process beyone GIA Ex and certain color clarity parameters). And so, once again, the brand is not buying you much over looking for a GIA Ex cut from elsewhere.
hm interesting -- thanks for the responses so far! they've been informative

you mentioned that some may be interested in going through GIA ex cut stones to meet even tighter cut criteria; by tighter cut criteria, do you mean personal preference? are there certain dimensions within GIA ex cut that are generally more preferable for whatever reason?
 

dreamer_dachsie

Super_Ideal_Rock
Joined
Dec 16, 2007
Messages
24,364
phaketrash|1306269073|2929315 said:
Dreamer_D|1306254855|2929166 said:
All diamonds graded by GIA and having an excellent cut grade are essentially the same no matter who is selling them. The brand name of Harry Winston etc does NOT change one little thing, it is still a GIA Ex for cut. So yes, you pay a LOT for brand name.

Within the GIA Ex cut grade there is some variation in how perfectly, ideally proportioned the stones are, as the article slg linked suggests. So it is worth it for someone very interested in top cut to weed through GIA Ex cut stones to pick out certain stones that meet even tighted cut criteria. BUT to my knowledge, Harry Winston et al. do NOT do such weeding (though they may says something about "hand selecting" or such, I doubt they can provide criteria for that selection process beyone GIA Ex and certain color clarity parameters). And so, once again, the brand is not buying you much over looking for a GIA Ex cut from elsewhere.
hm interesting -- thanks for the responses so far! they've been informative

you mentioned that some may be interested in going through GIA ex cut stones to meet even tighter cut criteria; by tighter cut criteria, do you mean personal preference? are there certain dimensions within GIA ex cut that are generally more preferable for whatever reason?
Wellll... it is personal preference in that for some people, GIA Ex cut grade is enough information for them and they would be happy with any diamond that falls in that category. For others, including most of the regulars on PS who tend to be cut nuts, we look for stones with proportions that meet a stricter set of standards that will optimize the liklihood that the diamond will have excellent light performance in the widest range of lighting environments. The tool slg linked, the HCA, can help to narrow the field of GIA Ex cuts to those that have a tighter set of proportions and will likely perform better overall. Not everyone cares about cut this much. And some people visually prefer cuts that don't fall into this sub-category of more ideally proportioned RBs. My personal preference is to either select AGS graded stones because they use a stricter cut rating method. Or to look for GIA stones that also score under 2 on the HCA, which suggests their angles are particularly complimentary.
 

phaketrash

Rough_Rock
Joined
May 23, 2011
Messages
12
thanks dreamer, that is really helpful

so in sum, from what ive gathered on this thread and some very brief perusing of other random threads:

1) GIA Ex cuts have a lot of variability among that grade due to a plethora of reasons, but it really comes down to personal preference on what some may want out of their GIA ex cut vs. what others may want out of theirs

2) GIA Ex cuts from particular jewelers are all essentially the same, so a Tiffany's GIA Ex vs. a HW GIA Ex vs. a Bluenile GIA Ex are all the same (excluding the innate variability all GIA Ex cuts may have from one another)

3) Use HCA calculator in conjunction with GIA Ex cuts to see ones that may have 'tighter' parameters, but anything under 2 is kinda all the same thing on HCA right?

4) AGS reports are even nicer because that lab's cuts are a bit more 'strict' or the like, so that will help as well (though im not quite sure what constitutes a good score on an AGS report versus a bad one haha)

if that all sounds right, thanks!
 

dreamer_dachsie

Super_Ideal_Rock
Joined
Dec 16, 2007
Messages
24,364
Sounds like you got it!

AGS is a large and well respected lab like GIA, they grade cut using a numeric system, so a cut grade of 0 is the best, and a cut grade of 1 the next best and so on.
 
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