[Jewelry making - Article 00637] - Re: [Orchid] Diamond cuts technicals

[leonid surpin]

========[ Invite a Friend - http://www.ganoksin.com/invite.htm  ]========

>     If you can see through the stone, it is "windowed". It also
>     indicates that the stone was not properly cut. In most cases the
>     pavillion angles were not correct. 

    In order to see through the stone, what needs to happen is that ray
    of light must enter the diamond, hit pavilion inside the critical
    angle, exit pavilion, hit a part of a setting, ( or any other part ),
    reflect under such angle so it could enter pavilion again, reach
    crown facet inside the critical angle, exit crown, and hit the retina
    of the observer. Given diamond refractive index of 2.42 it is not
    possible, unless cut is mangled in some horrendous way. I cannot even
    imagine what needs to be done to a diamond to make such transmission
    of light possible. Diamonds do have light extinction areas, but it is
    different from see-through. Term "windowed" is not applicable to a
    diamond. 

    It would take to long to give mathematical proof of that, so if
    anybody has doubts on this subject, the book by Marcel Tolkowsky
    "Diamond Design" should make the issue clear. 

Leonid Surpin.
____________________________________________________________________
T h e   O r c h i d   L i s t
Open Electronic Forum for Jewelry Manufacturing Methods and Procedures
____________________________________________________________________
Orchid FAQ:
~ http://www.ganoksin.com/orchid/faq.htm
Orchid Archives:
~ http://www.ganoksin.com/orchid/archive
Orchid Galleries:
~ http://www.ganoksin.com/orchid/gallery.htm
Invite a Friend:
~ http://www.ganoksin.com/invite.htm
____________________________________________________________________
Tips From The Jeweler's Bench - Article Archive
~ http://www.ganoksin.com/borisat/tip_sear.htm
The Jeweler's Selected Bibliography List
~ http://www.ganoksin.com/jewelry-books
Buy Orchid Jewelry:
~ http://www.ganoksin.com/shop
____________________________________________________________________
-Unsubscribe:
-Email: orchid-request AT ganoksin.com Body=unsubscribe subject=blank
____________________________________________________________________