Holloway Cut Adviser and the real world

[Pair0Ducks]

I am curious as to what people think the sensitivity of the HCA is. In other words, do people think they could see the difference between a 2.0 stone and a 1.0 stone? or a 1.5 and a 1.2? Is it quibbling to be looking for that 0.7 when you have a 1.2 in front of you?

Just looking for opinions from people who have some experience before I drive myself batty.

 

[Nicrez]

I think you are missing the point of the HCA. It's really just to weed out the ugly stones. A 2.0 and under are all the 2% of the stones out there that are cut to exactling proportions for the optomized brilliance, fire, scinitllation and spread.

Note that this is for RB's only, and there is no accounting for tastes and budgets, just like some people may like a 3 rated stone, versus someone who likes a 1.5. Each stone has a presence and OEC, Cushions, etc are never going to rate well on it, BUT they are still attractive to many. Same goes with the HCA "low-performers".

It's a tool, not a determinant. But when shopping online, it acts as your best calculating "mechanical eye" that lets you know how those numbers will react, compared to other stones, and compared to the optimal numbers for all four catergories.

If someone can tell a 1.0 rom a 2.0, they must be a cutter or a gemologist, or very very sharp, but if it was in front of you, you wouldn't need HCA, huh?

"We recommend you use the Holloway Cut Adviser as a final check on your selection."

 

[niceice]

It seems to us that the HCA isn't necessarily intended to weed out "bad stones" as much as it is intended to open the realm of possibilities for people who might want to consider diamonds cut outside the realm of the traditional ideal and super ideal cut diamonds... It's kind of a given that an ideal cut diamond cut within certain tolerances is going to perform well (with rare exception) but it is much more difficult to sift through non-ideal cut diamonds "off paper" and find a winner... IMO the HCA can be used by consumers as a kind of pre-screening type of "tool" but final judgement should be saved for a trained set of eyes and by trained we mean somebody like a "real" dealer (not virtual) or an independent gemologist who sees a lot of diamonds on a regular / daily basis.

 

[valeria101]

It's probably safer to take about 0.5 as decent range of variation for a HCA result, just taking into account that the numbers you plug in are not dead on and repersent averages anyway. Starting from here, the Q wether 0.2 difference has some visual impact takes a rather different turn. In theory it might - but this depends on the viewer, size of the stone and so on. Using some scree-size DiamCalc simmulations one can probably discern some clear choices - but their practicality needs reality checking...


You might want to take a look on /www.pricescope.com/forum/rockytalky/gia-publish-1998-brilliance-and-2001-fire-papers-online-t8186.html]THIS" thread[/url]> where I got my answer about wether the HCA is limiting cutters' choices. Obviously, those are buyers' choices right now if one goes by the HCA philosophy.

as Niceice explains too.