Bow Tie Effect?

[suzanne]

My Boyfrriend and I are interested in an oval but was told it has a 50/50 bowtie. I know what a bow tie is, but am worried how noticable it will be. The depth is 63%

 

[Garry H (Cut Nut)]

A bow tie is when you see uor own head which blocks illumination.
You need to go to a store and look at fancies - go with a piece of copy paper and poke a peep hole in the center - you will see the bow ties in marq, pear and oval's disappear when you look thru the hole.

Do a search and you will find lots about bow ties

 

[Garry H (Cut Nut)]

http://www.diamondtalk.com/forums/showthread.php?t=47889

If you are the same people asking bow tie questions at this link then please be assured the bow tie effect is more dependant on you, your vision (close up / long way away) and your head, than the diamond.

The 2 lots of advice on the other forum are way off in the first instance, and "trust me and only me" in the second.

It is very possible for a diamond with no head shadow to be too shallow and look dead as a dodo once it has some dirt on the pavilion.

 

[Rank Amateur]

Hey Garry

I see Jan posted an oval with no bow tie and with a pegged BS score. Does a bow tie indicate light return, or is there leakage disguised in the darkness of the bow tie as well? Jan's stone looks almost glassy in the middle. Bow ties are very curious things.

Maybe "poor" (i.e. not symmetrical) facet alignment can prevent the bow tie but a skilled cutter can still get the light to return.

 

[Rank Amateur]

Can light leaking in the pavillioin help the BS to a significant degree?

 

[Garry H (Cut Nut)]

Good observation RA

A diamond that has no equivalent of a bow tie (i.e. no star) is too deep and lacks contrast.

If the stone has say a 2:1 l:w it simply should have some bow tie.
The exception is stones that are cut with a keel type culet.

 

[Rank Amateur]

How common is a keel in the pavillion? One in a hundred?

The keel seems like a good idea in that it might help the light performance and maybe retain a little extra weight as well. It must be more complicted to cut than one without the "keel".