[Jewelry making - Article 00180] - Re: [Orchid] Stabilized Vs. natural turquoise?

[Peter W . Rowe]

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

>    Excuse me Kathrine, corundum has a hardness of 9 and anything over
>    5.5 will scratch glass. It looks like you might have typed a
>    sentence and then changed it. You are correct that some natural
>    turquoise will be up to 6.5 but I never

>    have heard of any over that. Anyone else?

    Turquoise is often somewhat porous, and in my experience, it's not
    uncommon for the best and hardest samples to get a good deal of
    their hardness because of silica that has infused the turquoise. That
    could increase the hardness to near seven, I'll bet, though I've
    never tried to test it. I'm aware of some treatments that have been
    used with turquoise that do exactly that, infuse silica into the more
    porous turquoise rather than the more common resin treatments. My
    understanding is that these are then tricky to detect because it
    tries to mimic something that can occur naturally. I've not
    encountered any that would appear to be any hard than that, or
    frankly, even quite as hard as quartz itself.  But anything is
    possible, and I do have some old bisbee stones that, along with an
    undramatic lack of intense color, seem quite hard, and even have some
    individual clearly defined quartz crystals imbedded in it. Someone
    testing the hardness of these could easily be fooled by those
    imbedded small crystals. 

Peter

____________________________________________________________________
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
____________________________________________________________________