What is RCDC "Adjusted Depth" for radiants?

[zmre2b]

The experts on radiant cuts over at:
http://www.radiantcut.com/images/optimal.html

state that their ideal radiant cuts meet these measurements:

RCDC Original Radiant Cut Diamond Measurements
Adjusted Depth Percentage: 50% - 64%
Adjusted Crown Height: 7.5% - 15%
Adjusted Pavilion Depth: 40% - 53%

Traditional GIA Measurements
Traditional Depth Percentage 55% - 69% *
Table Percentage: 58%-69%

* Traditional depth percentages of up to 72% are acceptable if the length to width ratio exceeds 1.30 - 1, and the length adjusted crown height is at least 8.5%.


How do they calculate the "Adjusted Depth"? Is it percentage of the length instead of the width (like GIA) or is it the average of the two or something else? What exactly do they mean by "length adjusted"?

Most radiants seem to be really deep (>70%) but at the radiantcut they seem to advocate very shallow radiants as their version of ideal. How shallow is too shallow in a radiant? What is the result of too much shallowness or too much depth (aside from paying for weight you can''t see).

thanks for any info.

 

[Rank Amateur]

I don't have any answers, but I am curious about what can be regarded as Ideal in a radiant. "Ideal random shattered glass pattern" seems a bit of an oxymoron.

 

[Nicrez]

Actually, ideal in a Radiant is tough, as they are not easily put into categories, and are not cut like a round stone to have H&A, because the facets on the pavillion are very similar to a brilliant cut round stone, but NOT identical. Also, the facets on the crown are cut more like an emerald or princess, than a round stone, the the patterns will not be visible.

I have a RCDC Radiant. I searched for SO long to find something that was NOT deep. I saw too many deep stones, and the same method that makes a RB improperly cut when too deep, makes the radiant improper and lifeless. A radiant's patterns are best viewed when both crown and pavillion angles are cut properly and if the table and depth are cut within the ranges of RCDC's limits, the stone not only has fire and brilliance, but you don't have as many fisheyes, and dead areas of sparkleless clear zones.

EVERY diamond must ensure that there is enough depth to accomodate the light coming in, to reflect and refract properly, so why would a radiant be any different. Cutting stone with a deep depth could be for obvious reasons that a cutter wants to retain the most amount of carat weight to increase price (as it goes by wt and not cut), so profit dominated the radiant cuts out there.

The Radiant Cut's stones ARE generally cut shallower and with smaller tables (MINE happens to have a 62% table, with a 58.3% depth), it is BY FAR the best radiant I have seen out of the 71%+ depth stones I have seen...

If you have seen as many radiants as we have seen, the difference between a properly "efficient" cut radiant (which is the LEAST profitable, as it has less carat weight) is MUCH nicer than some of the carat heavy uglies out there. Perhaps that is why Radiants are not as popular...because people see the lifeless stones that are cut for weight and not beauty.

In our opinion, my fiance and I discussed a budget, and willingly paid the premium for our stone, (well above other market stones larger than ours) so we COULD get the nicest stone. I would never consider a deep cut generic stone, now that I am spoiled by the Grossbard cut one I LOOOOOVE.

 

[valeria101]

The guys leave people guessing, so that's what I did.

Somewhere on the site it is mentioned that the adjusted measures are the same as the regular rules for square radiants.

I belive the adjustment takes the geometric average of width and length, (not the width as usual) as reference for the percentage - to take into account the variance in proportions.

Also, the face-up size is adjusted for those cut-off corners (taking 95% or conventional area). I am not entirely sure wether this adjustemnt is done for the respective geometric average, but it might. The difference is not overwhelming...

What is 'too shallow' would depend on all other details (proportios and crown height...). However, at 60% in a square stone I'd start wandering, no matter what. AGA starts wandering at min 64% depth ( but I suppose those cut guidelines are meant to fit stones from square to about 1.5-1.6 L/w ratio - th emore common set that is).

 

[zmre2b]

So the "adjusted depth %" is: depth mm /((width mm + length mm)/2) ?