Curiosity - MRB with open culet?

[the_mother_thing]

Don't know why, and maybe a silly thing to be curious about, but I have been wondering what a MRB would look like with an open culet like OMC/OEC diamonds. I haven't seen one. Does it create a kozibe effect? Anyone have one, pics?

 

[diamondseeker2006]

There are transitionals that have small open culets. They were between OEC's and modern rounds. I think whether it would show the kozibe effect has to do with the angles of the stone. The cut of mrb's may not allow for that, but one of the cut experts like Karl or a diamond vendor may be able to answer that specifically.

 

[the_mother_thing]

Thanks DS. I am familiar with transitionals, but thinking more so about today's RBs. Why don't they have cutlets and what might one look like with one?

 

[VRBeauty]

I seem to recall a post about Single Stone modifying a PS'er's round brilliant by adding a culet.... I don't recall who it was, though. I think it happened within the last year or two.

 

[VRBeauty]

Here: https://www.pricescope.com/community/threads/rb-to-oec-recut-before-and-after-pics.177547/

ANd here: https://www.pricescope.com/community/threads/reveal-single-stone-reset-lots-of-pics.179152/

 

[the_mother_thing]

Thank you VRB, but I guess my question isn't clear. I don't mean a full recut of the entire diamond. Merely, just the addition of an open culet to a modern round brilliant. Adding that facet in place of the point.

 

[yssie]

Thank you VRB, but I guess my question isn't clear. I don't mean a full recut of the entire diamond. Merely, just the addition of an open culet to a modern round brilliant. Adding that facet in place of the point.

I can't speak for VR, obviously, but I think that was the thought - twosanguinehearts had her Tolk-type MRB recut into an "old cut". The recut consisted largely of shortening the LGFs (widening the pavilion mains) and cutting an open culet. I don't see that flowery kozibe effect in the pics of the result - certainly not like in some true antiques - but presumably it is present to some extent IRL on tilting the stone (it's the internal reflection of the culet)? I'd love to see a DC model of this, if anyone wants to play!

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Here's an interesting read - how GIA assigns the Round Brilliant, Old European, and "Circular Brilliant" labels:
http://www.gia.edu/gia-news-research-round-brilliant-cut-diamond-pay

 

[diamondseeker2006]

With modern round brilliants, the objective is to reflect light out of the top of the stone, so I imagine that a culet facet would not benefit that purpose.

 

[Gypsy]

I think a small one would be okay, probably. Jonathan at GOG or Brian at Brian Gavin would be the best to ask about this though.

 

[thecat]

No kozibe effect as far as I can see in a mrb with damaged culet. Or I might not have look long enough then.