CUT NUT (& others).....re: radiant diamond

[aljdewey]

Hi, all:

In a recent thread, Cut Nut said that radiant shaped diamonds are the worst performing. Can someone enlighten me at to why that would be? I'm considering a radiant as an alternative to a round, and where a square radiant is fairly symmetrical, I thought it would be a decent cut.

Thanks in advance for your input.

 

[oldminer]

Radiant cut provides a wonderful cut shape popular with fancy colored diamonds. Why is that? It is because radiant cut can be manipulated to darken the central zone of the stone better than rounds. Dark is not good when you are talking the desire for light return and brilliancy, but it is the "thing" when you want to increase the apparent coloration in a fancy colored diamond.

Radiant can be pretty and serves well as a shape, but I'd agree with Garry that it is not a top performer in colorless diamond compared to some other shapes such as a well cut princess or Lucere, or flanders.

 

[Garry H (Cut Nut)]

Fancy shapes are not my thing - Dave's the Man what he says is spot on.
But the problem with radiants is they have a single culet which means the pavilion angle is shallower in long direction and steeper across the stone. So it is impossible to have an ideal cut.

The best emerald cuts or stones like the new spring cut have a "keel" - a long culet. The length of the cculet in an ideal stone is the difference between the length and width of the stone. Then, and only then, the pavilion angles can be the same all around the stone.

eg. 8 x6 mm stone should have a 2mm long keel. 9x 6 should have 3 mm long keel.

 

[aljdewey]

What if the radiant diamond is more square in dimensions than rectangular.

For example, what about a radiant cut stone that is, say, 5.5mm x 5.39mm. Is that a potentially better performer because it's more symmetrical, or would such a stone still be susceptible to the "dark" zone in the middle?

 

[pinebud]

Hi there,

I am also considering a square-ish radiant diamond, but am having a hard time finding a good balance of features. It sure does seem hard to get a good cut in this shape. However, my experience in searching has been that they are far cheaper than other diamonds of similar sizes. Any ideas about why that might be?

Does anybody have any thoughts on what would be a good cut would be in a square radiant?

Pinebud

 

[Mara]

Woooaah this post is OLD!!! I can't believe someone found it.




Pinebud, you may want to start a new post fresh with your Q's in it....and also as you already found the search function, check out other radiant posts. We have had quite a few radiant lookers recently. It definitely IS harder to find a well cut fancy than a well cut round...you just have to be more patient and look a bit more thoroughly!

 

[Nicrez]

aljdewey, not an expert here, but I've definately seen enough radiants (as square as I can find them). The parameters me and my BF are looking for make it so much harder, but the stones that we have seen have been badly cut because there is no uniformity in this stone. Patterns have varied from so many cut styles like a princess pavillion, to star bursts, to brilliant cuts (like a round brilliant) to everything in between.

Honestly I have so far seen 6 different variations of cuts in over 20 different stones.

Imagine the lack of standards. Now compound that with the "improper" dimensions of a large table (for a nice larger looking stone), or the overextended depth, with hidden carat weight.

I have seen the proportions so distorted on these stones because cutters have yet to perfect the dimensions, and the industry has yet to define the proper"ideal" standards. You have cutters in India, cutters in Canada, New York, Amsterdam, Africa, Israel, all with their own "interpretation" of a radiant. No wonder these stones are so varied!

Now consider that a "properly cut" radiant in theory would have the brilliant cut of a round diamond on the bottom, the wide table and shape of a princess (or emerald), and in theory calculating proper angles for the crown and pavillion, determining a proper percentage for the depth and table, one SHOULD achieve a brilliant stone, second only to a round brilliant. In theory.

Looking at a princess cut bottom radiant today, compared to a more common "radiant" cut stone next to it, I noticed the facets made the Princess cut stone look well, like a princess with the angular facets, and it had those sharp pointed sparkles. The radiant cut stone actually looked like cracked glass (like IceLady had pointed out before), which added little sparkles all over the inside depth of the stone. It also had better fire and Scintillation than the princess cut stone. Now consider this stone was not even properly cut and can at best on average be considered a 3A all in all.

aljdewey, I KNOW there are phenomenal radiant stones out there that can outsparkle and outshineany other fancies. Finding it is the key, but keeping your color, clarity and size options as open as possible, may offer a better time in finding it. Lord knows, limiting yourself as much as possible in these parameters makes the search so much worse. If your standards are ridig, then keep your eye open and be patient. But I recommend the radiant hands down (next to the RB, of course) to anyone looking for a fancy stone with Brilliance, Dispersion and Scintilliation with some shape!

 

[Rank Amateur]

What about a radiant give it that "broken glass" look? If a radiant is very square and symmetrical will it still have that jumbled appearance?

 

[valeria101]

----------------
On 2/2/2004 11:20:43 PM Rank Amateur wrote:

What about a radiant give it that 'broken glass' look? If a radiant is very square and symmetrical will it still have that jumbled appearance? ----------------

Interesting question... here's my take:

There might be too culprits for this phenomenon: one - the light loss resulting in allot of contrast between alternating reflective and light loosing areas, and two - the pattern of facets on the pavilion allowing for the discontinuous reflection on light. As far as my guessing goes, the rads with pavilions UNLIKE a princess cut have the look while those princess-cuts-with-clipped-corners don't or almost. Also, some of the most "crackled" radiants I saw seem to have shorter facets on the pavilion getting close to what the Lucida's pavilion looks like. There are variations on the cut, and by no means I have an appropriate collection of cut charts to post. All in all, the more asymmetrical the design of facets on the pavilion, the more pronounced the "crackled" look is. Here, "asymmetrical" does not mean "badly done", but just that the angles at which pavilion facets meet are very diverse by design. Loosely according to one of Garry's posts, the same angle variations result in light lickeage - which happens to be the first component of the "crackled look", in my view.

Of course, this kind of facet design can occur on both rectangular and square stones. An even design of pavilion facets would not be achievable on a rectangle, but un-evenness is universal... for better or for worse.