Step cut shallow, why don''t they cut more?

[purrfectpear]

So we started to threadjack the other topic when we got to discussing shallow step cut diamonds.

Diagem, Storm and RockDiamond mentioned that you could get a gorgeous looking step cut (we happened to be talking about EC, but I''m guessing it would be true for Asscher?) diamond at 50% depth.

I did a little net research and found sites that gave generally accepted depths for EC no lower than low 60''s and only one that said you could go as low as 53%. Then I looked through at least a hundred virtual inventory spec dimensions and the lowest EC I found was higher than 60%. I found nothing in the 50''s at all, much less 50%.

Here''s the part I don''t understand;

If a 50% depth EC can produce a sweet diamond, and a 50% depth will obviously produce a diamond that at 1 ct. will probably have the spread of close to 1.5 ct., then why are cutters routinely cutting to 65% to 68% average? Why not cut more shallow diamonds? Wouldn''t consumers prefer to buy a diamond that looked larger?

Karl can you model one at 50% so I can see how that works?

 

[stone-cold11]

Karl posted his reply in the original thread. https://www.pricescope.com/community/threads/wait-round-vs-fancy-fancy-is-cheaper-for-same-size.108355/

 

[strmrdr]

See this thread for examples and comments by Paul:
https://www.pricescope.com/community/threads/45817/

 

[purrfectpear]

Hmmmm, interesting. The 50% example you modeled was fugly and dark though. Who knew? The 46% still looked pretty

So basically it''s just that they would be too expensive to cut? Couldn''t you just cut more of them out of rough since they''re shallow? Like 3 shallow stones instead of 2 deeper ones, or doesn''t it work like that?

 

[Rockdiamond]

It''s important to remember that the shape of the rough diamond determines the best course of action- and the resultant polished stone.
It would make no sense at all to polish a diamond to 50% if it plots out to 60%
So, it''s like an accident of nature when the rough diamond is a sliver- a thin piece that could never make a nice round diamond.
Trilliants are generally cut from very shallow rough - again, cutters of trilliants have to seek out very specific shaped rough diamonds to make the trills. Since trilliants are a specialty, those cutters generally search for that type of rough.
Shallow Emerald or other step cut- is not a specialty unto itself, therefore harder to find

 

[strmrdr]

here is a 48.4% ec 10% CH 60% table.

 

[strmrdr]

48.4% aset

 

[asforhim]

I completely agree that shallow step cuts and even radiant and modified cushions can result in a remarkable diamond. As posted earlier, I was searching for a great radiant and settled on a shallow cut (55%).... I can''t find anything online even close to 55%. Most are in the 62-70% range. Anyway, I love the 55% rad from Harry Winston... Link: http://www.youtube.com/watch?v=pyzRRuY4oFI