[Jewelry making - Article 00869] - Re: [Orchid] Are they Rubies?

[Gary Bourbonais]

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

>         Your post engendered alot of discussion regarding the tools
>     and expertise needed to ID a stone.  But no one answered your
>     question. 

Hi Folks....

    One useful tool that can be home brewed...and that's a polarizer
    set... You need a pair of polaroid type sunglasses, or a couple of
    old photo polarizers, or if you're lucky you can find some surplus
    polarized plastic... You need two pieces of polarizer material.. 

    Figure out a way (hanger wire, old linen magnifier frame, whatever)
    to hold the polarizer material about 3 inches apart....afix the
    polarizer material at crossed (darkest) position..... 

    When you stick a doubly refractive gem between the polarizers, with
    a light source coming through....it lights up.... A singly refractive
    gem will stay dark... Note...you may have to check the gem at more
    than one axis... 

    Garnet, glass, spinel, CZ, and diamond are singly refractive....most
    everything else commonly run across gemwise is doubly refractive.... 

    Easy to tell ruby from garnet this way.... 

    Also...some of the new glass simulants are achieving higher RI than
    used to be possible...or, their RI is crafted to be in the range of
    what they're simulating... 

    The polarizers will sniff 'em out, though... 

Gary W. Bourbonais
A.J.P. (GIA)

____________________________________________________________________
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
____________________________________________________________________