Hi Mocha, as far as I know, H&A is,
* superior cut proportion (this increases light return, reduces light leakage, and stones with more fire tend to appear bigger than duller stones of same caratage).
* symmetry (can see the H & A under viewer)
H & A assures that your stone has well-cut proportions, whether you feel it's worth a $1K premium is personal
Also, a non-H&A stone may not be NECESSARILY inferior, just that it's a touch less symmetrical, and/or not under the H&A
BRANDING. Depends on the stone... could be a really poor stone, or, could be an almost H&A stone, or, could be a "H&A" stone that was not put under that brand.
* Check the cheaper stone proportions (should have GIA cert right? Compare both stones' depth & table, if the cheaper stone is very close to the H&A stone, by all means, save the $1K difference). If not from same jeweller just copy down the info. to compare.
* If from same jeweller, place both stones side by side too... if you can't see a REAL difference with your own eyes, forget the more expensive
your peers won't be able to tell either. Can put the $1K to a bigger ct or a nicer setting so on. Unless you would like to inform your friends that yours is a H&A
Some diamond lovers who own a personal loupe enjoy admiring the H&A outline of their stones though
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Regarding colour:
light return is a
separate issue from
colour... a D colour stone has as much chance of being "dead" compared to a G colour stone if CUT PROPORTIONS are not ideal. Thus, a G colour with great cut proportions will scintillate more than a D colour with poor cut proportions. UNLESS, you are talking about VERY wide variance... say, a white diamond compared to a black diamond.
Comparing a D and a G with SIMILAR cut proportions, they should both shine similarly, except... one is whiter the other less white- a colour perception.
Some people have a preference for "low" colour grades simply because they find the Ds too white (cold, or too perfect like Cubic Zirconias ie. CZ) and prefer Gs (warmer).
Digressing onto CZs and lab-real diamonds: Abit of irony, the new super-breed of CZs are deliberately created at warmer colours because a "D"-"IF" (Internally Flawless)-1ct is a dead giveaway that it's a CZ (the real ones at D-IF-1ct cost more than most can afford). They charge higher for warmer CZ haha cos easier to tweak CZ colour than it is to reduce CZ clarity to more believable VS2.
Then there are lab-created diamonds (ie. real! but created in lab not nature. Not the same as CZs which have different composition from all diamonds). Not commercial yet, the problem they face is in growing it to bigger sizes ie. easier for them to grow many tiny stones than 1 big stone. Some speculate that will drop the value of nature-created SMALL diamonds because there's a lab-created REAL diamond alternative at lower price. But that nature-created BIG diamonds will hold their value (hence some speculate should buy BIG diamonds now only haha, not that diamonds have any real holding/ resale value anyway). Some purists are dead against lab-real diamonds as it's not created by nature.
Further digressing on resale value: Do note that your real nature-created diamond CAN shatter/ crack/ be scratched. Do not hit it against hard surface (yes, diamond is the hardest natural substance... but man-made substance maybe not... anyway, even if it IS harder, it's the FORCE at vulnerable point of contact that can shatter the stone). Placing a few diamonds jumbled about in a case will have them scratching each other. Beware, if you buy resale from another person whom you know has worn the stone before... whatever NEW cracks sustained by that wearer will not be reflected in the GIA cert when she bought it new. Some people have had their clarity grade of the stone reduced eg. from IF to VS, because they sustained some damage/ cracks during wear. Anycase, I haven't heard much of people reselling their stones...
Regarding clarity: Clarity is important more in the need for it to be eye-clean, no one wants to be able to see carbon particles with the naked eye. Unless the heavily clouded SI etc type that will affect the light return, otherwise... VS/ VVS/ IF is pretty interchangeable.
Some people must have IF (cos... more the concept of it being flawless), some don't mind SI if it's a carbon bit that's nicely situated at the girdle (can set the diamond such that a prong covers exactly there).
Regarding cut proportions: If you see the sectional diagram of the stone, it affects how light enters and is refracted.
Consumers focus on clarity and colour grades
almost solely to make their purchases cos proportion needs more understanding of the numbers- much easier for retailers to draw a chart and tell the consumer to keep to D colour, IF clarity for the "best", ignoring cut proportions (some will just assure you it's "ideal cut, of course" but sometimes that's only just what they
say).
Some knowingly buy a shallow (poor cut proportioned) stone cos for the caratage, they get a stone with more TABLE AREA... they sacrifice light return (looks duller) but maybe they prefer it to physically look bigger by virtue of the bigger surface area. Their mentality is instead of getting a small stone and make it seem bigger by having more fire, why not simply get a bigger stone with less fire- different strokes for different people.
Others focus on cut proportion, as long as colour and clarity satisfies a min. standard, priority is placed on cut proportions.
ie. They prefer a F-VS2-ACA or great cut. Instead of a D-IF-mediocre or poor cut (very possible cos to preserve the IF clarity they sometimes have to cut the raw stone to avoid the impurities, or try to save the carat weight by compromising on cut proportion. Since most consumers don't comprehend cut proportions but do understand the clarity or colour grading system, it's easier for retailers to hawk a mediocrely-cut IF than an ideal-cut VS stone).
Or, they prefer a bigger normal round brilliant at bigger caratage instead of a Gabrielle (some don't like the
manner in which it flashes light... some described Gabrielle as "more, in tiny flashes", compared to a normal cut which is "less, in big/ dramatic flashes").
No real hard and fast rules, as long as you know all these and come to whichever decision based on your personal preference, good enough.
