[Jewelry making - Article 00036] - Re: [Orchid] Strange opal experience

[Andrew MacKINNON]

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


    Sounds like potch opal. We recently 'treated' a large piece here in
    shop. Simply place in a super saturated sugar solution for a couple
    of weeks at 20 Deg. C or higher and then pop into a bath of conc.
    Sulphuric. The sugar is carborised and turns black high-lighting the
    the opalescence. A lot of Australian boulder opal in the rough has an
    opalescent sandstone backing. If the colour is strong you can make a
    reasonably saleable rock from it by the above means. It's similar to
    the way onyx is died traditionally. 

    Regards, Mac 

    P.S. Treated potch opal is cut , pre-polished then treated. The
    final fine polish is done after treatment as the carborised layer is
    generally only a few mm thick.  


____________________________________________________________________
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
____________________________________________________________________