cut and color questions!

[:)]

Hi - I have really enjoyed perusing this website - I have obtained a lot of valuable information. I was hoping that I could get a little advice myself, as I have found all of you to be so helpful to others! We are getting near purchasing, but before making that expensive plunge

, I would appreciate any input!

1. Is an H color more visible (to those that can detect it) in a larger stone? For example would an H be more visible on a 3 carat as opposed to a 2.5 or 2.6 (for arguments sake, lets say each stone is cut and proportioned the same)?

2. If a RB stone is really well cut, would the sparkle possibly make the H not so obvious? (Due to the firey colors flashing around).

3. I also had a question re: the cut advisor. If I get a Holloway of 0.7 on one stone, and a Holloway of 0.2 on another stone (each stone done with actual crown and pavillion angles, as opposed to depth %), should I expect a visible difference to the eye in the stone when examining it?

Thanks in advance!

 

[kristy_lyn]

They actually say that anything under a 2 on the HCA can narrow down your selection to give you some good possibilities, and most people would actually prefer something with an HCA score around 1.... but the HCA should be used in conjunction with all of the other information.

That means that, depending on the characteristics you prefer in a diamond, you''d probably like the .7 better than the .2! Lower is not always necessarily better...

 

[lauraher]

In regards to color I can understand where you are coming from. My old stone was G color at 1.5ctw and my new stone is I color 2.18ctw. I was afraid of being able to see any yellow in the stone, but I just received my new stone on Saturday, and it is blinding white in the face up position. From the side view it doesn''t look yellow, but it doesn''t look blinding white either, but there is definitely no yellow. I suggest, as everyone told me to do, to go and look at some superideal cut stones at a local store and see what your color tolarance is, and then speak to the vendor that is selling the stone and ask them to rate it high or low for that particualr color, i.e. high H or low H. IMHO, as long as you get an ideal cut stone, going down to H and even lower will not be a great factor. Good luck!

 

[hausee]

I am gonna visit local gem store to check out their different clarity and color diamond...

But I remember I saw a 1ct diamond with I color looks icy white to me in plantium setting...off course it is ideal cut.

 

[WinkHPD]

Paul Slegers had an excellent dialog about this and why it might be with stones that are near the edge. If the tolerances are not tight, some of the pavilion facets may be below the edge where performance is damaged, but if the stone is properly tight in tolerances it will have all of the pavilion facets at or above the edge, resulting in truly astonishing performance. The HCA rewards stones that are near the edge as they are where the most contrast and beauty occur, but because it is using the averages, it can reward stones that should be penalized, leading to the misconception that a 0.7 might actually be better than a 0.2, whereas in reality, a stone with tight tolerances and a 0.2 HCA score might in fact be even more dazzling than the stone with the 0.7, although both are very sure to be incredible!

Thus the question to ask your vendor is what are the minimum and maximum angles on the pavilion, and if any of them are below 40.4 then go with the stone with the 0.7. If you have diamond with a pavilion angle of 40.5 average and the low angle is 40.4 and the high is 40.6, then I would be giving serious consideration to at least looking at the 0.2 rated stone.

Wink

 

[Sum]

Very good point Wink, but isn''t it also not entirely correct to assume the stone with the higher HCA is the "safer" stone.

Take this stone currently for sale by a PS vender:

Depth 62.9%
Table 55%
Crown 35.5°
Pav 40.2°

Scores a 1.0 on HCA, the "sweet spot" according to many.

But if you look at the Pavilion angle you see it is already below the 40.4* "EDGE", without taking rounding or averaging into consideration. A stone with a 40.5* Pavilion and an HCA of .5 is a much safer bet, no?

I think it becomes an issue when people blindy follow a rule like only buying a stone between .8 and 1.5 on the HCA, and never question the reasoning behind it.

But sorry for derailing...

 

[:)]

Thanks - this is very helpful. I am leaning toward the one that has the lower score because it is a bigger stone (2.6 v. 3.06).
I think I will call the vendor and see if they can look at them and tell me if they feel there is a visual difference. I also need to ask them if both are ''eye clean'' - that may make the decision for me. The smaller stone is an AGS 000 (the holloway .7), the larger one was graded by egl usa. Both of them have really good table/depth/crown and pavillion angles (although having them check for min/max is a really good idea - I think I will ask if they can do that too). I was going to take whatever I get to my appraiser to see what he thinks, but since it is through the internet I need to figure out which one to purchase! I know AGS is the more reputable lab, but I figure if I purchase the EGL and my appraiser does not agree with their report, then I will return it.