Hi all, What a fabulous forum this is! I find myself wanting to read
every last nugget of info here. I was wondering if anyone could
recommend a good book or two on Opals - something informative,
technical, and possibly inspirational. Last year in Tucson I
purchased some rough opal from Rainbow Ridge - Nevada. It’s quite
beautiful and I can see it’s potential. I’m wondering how to proceed
with it… maybe a book might provide the answers to my plethora of
questions around the topic. Thanks so much, Mecca
Hi Mecca The Rainbow Ridge material can be “VERY” nice. It has some
of the best color of any opal in the world. BUT. The but is that it
is not very stable. I have seen pieces of it fall apart when dried
for only an hour or so. I have seen very top color pieces go to
looking like a lump of sugar in 30 minutes, only to return to top
color when put back into water. I have a piece of wood with opal
that has very good color, but when put in water, the color goes
away. I have also seen pieces of it fashioned into jewelry that was
decades old and still in top condition. It can be quite
unpredictable.
The unfortunate thing about the Nevada Opal, is that only time will
tell which type of opal you have. If the piece you purchased was
packaged in water, you will have to dry it out to see what you have.
Doing this may result in a fractured stone. This is the chance you
take. Once the stone starts to craze, there is nothing you can do
to stop it. If the stone does dry out without crazing, and here we
are talking at least six months or so, you might be able to get a
good stone from it. Cutting it will be little different from
cutting other opals. Watch the heat. Never use hard diamond wheels
under 600 grit. Did I say watch the heat.
There was a “trick” published years ago for curing Nevada opal. It
was called the Nevada Cure. You took a piece of opal and a wad of
wet paper towel and sealed them into a ziplock bag. You set the bag
out and let it stand for a few years. The though process was that
if the water evaporated from the bag, and the opal very slowly, the
opal might be stable when dry. This never proved to be a real cure.
There was even experiments in irradiation to improve the molecular
bonding in the opal but again this didn’t prove to work. I know of
no proven cure for the problem.
If I had a nice piece of Nevada opal, I would put it in a glass dome
jar, with just a drop of chlorine bleach in the water to keep down
the algae growth and enjoy it as a specimen.
Don