Virgin valley opal fracture when dry

Hi,

I’m considering putting opal to unconventional use in artwork. To
what extent does the Nevada variety (Virgin Valley) opal fracture
when dry? Will it completely disintegrate into dust given time? Or
will it simply fracture in millimeter-sized pieces?

Thanks,
Andrew Jonathan Fine

To what extent does the Nevada variety (Virgin Valley) opal
fracture when dry? 

TOTALLY depends on the individual piece!!

John Dach

It will fracture for a while, maybe a year or so. What’s left should
be pretty stable. Buy only material that’s been dried for a year or
two.

Al Balmer
Sun City, AZ

It really depends a lot on which mine the opal came from originally!!
I have Rainbow Ridge that is beautiful but it crazes heavily because
it is a “wet” mine. The ground bearing the opal has never truly dried
out. Royal Peacock, on the other hand, is higher up and is considered
a dry mine… I have one piece from there that has never crazed. I
have mined both of these. The Negro mine produces great black opal on
occasion that is very stable. I believe it depends on both the mine
and the individual piece but more so on which mine. Much of my
Rainbow stuff crazed when I dried it but some pieces are as large as
my thumb and they have remained stable for going on 5 years now. Take
your pick!!

Cheers from Don in South Florida.

depending on the pieces, it will fracture into 3-6 mm sized pieces.
it usually will form, more or less, concentric fractures around the
center of the stone.

anyway, let it dry out about 3 months, sitting on the shelf in the
studio, you can then opticon it if you choose. My first carving was a
virgin valley opal, paid $0.50 for it, and produced a stone worth
almost $1,000.

warm regards
Mark Zirinsky
denver

Andrew; What I’ve read is that the opal is quite prone to crazing but
that the material is usually left out for a period of time before
being cut. The opal should it survive this is what is cut. I have a
few pieces that I’ve had for years and have never crazed. You might
consider letting it sit for a few months before use just to make
sure.Find out if the cutter cuts this material on a regu;lar basis.

Dave Owen

I had a piece with good color that I left to the air for over one
year. It was not showing any crazing or cracking so I began working
it gently on the wheel hand held. It shattered into a zillion pieces.
Wha! Heat was not the problem, it just was going to break apart and
it did

A friend of ours had a piece of limb casting that had a "BEAUTIFUL"
grown over small “branch stub” that had a lot of red in the knob or
stub, and Cynthia was to make a pendent out of the stub section. By
accident, a book got “tossed” onto the original piece, and the
stub broke off just where we were going to cut it off. Made an
absolutely beautiful “stone” for the pendent, and she got the rest of
the limb casting as partial payment for the work. The piece is still
in great shape, as far as we know and the "rest of the limb casting"
is in one piece too. Our friend feels the materials from that area
need to be dried slowly for a good year or more to have a better
chance at getting a good, solid piece. Too fast drying and the chance
of crazing, breaking is great.

Great area! I went there once with him for 3 days and we did find
some pretty nice material. That material is “somewhere” in our
stored items, but last time I saw the material, it was in great shape
and that was years after our collection trip. It is just in storage
until we “get to it”, with all the other stuff we are doing.

John Dach

I’ve been gone so I’m trying to catch up on Orchid so if someone has
mentioned what I’m about to, please forgive me.

One method of drying Virgin Valley Opal or any Opal purchased in
water is to wrap the material in a few layers of paper towel, wet it,
and place it in a sealed zippered bag and store it for a few years.
After about three years, whatever is left should be sort of stable.

For painting application, feel free to use cyanoacrylate on any
cracks. It’s a fairly standard practice on Virgin Valley Opal
specimens to use it to keep the limbs together. It might help with
what you wish to do.

TL Goodwin
Lapidary/Metalsmith