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Cracked doublet


#1

Yes,you can recut a doublet,usually with no problem.I deal with opal
exclusively and in an effort to keep some of my pieces a little more
affordable I use doublets.I cracked more than I care to think about when I
first started.Theres a couple of tricks I’d be glad to share if your
interested (when setting).If you don’t have the equipt.I’ll be happy to
cut it for you,or whatever I can do to help. You can e-mail me offline if
you like. Mike


#2

I have been watching the thread on the cracked doublet stones with
interest but more interesting was Mikes offer of some tips in setting opal
stones.

I have a pair of 10x6 that I am about to set into 9ct mounts that I have
made and would be glade of any tips in setting these. I have had a little
but no real success in setting this stone and tend to avoid it when I can
and would appreciate any help you can give.

Major Boyce @pyramid

The greatest pleasure in life is doing what people say you cannot do.

EVERYBODY has a talent. What is rare is the courage to follow that talent
to the dark place where it leads.


#3

Dear Major,
as an Aussie, I’ve set a fair bit of precious opal over
the years. Cutting an accurate bearing for the opal is of paramount
importance. If the opal is pressed down on a high spot in the bearing, it
will often crack at that point. One of the tricks is to smear a very very
thin trace of araldite around the bearing. The plasticity acts as a “shock
absorber” when you are pushing over the bezel or claw. I do the same with
emeralds, but remember, only a tiny smear - otherwise it can show up
through the stone.

The choice of setting metal is not always ours to make, but if you can, go
for the softest alloy available. When I have the option, I choose to use a
fine, 0.5mm thin, platinum bezel on the more precious pieces of opal.
Platinum sets opal like a dream and I’ve never had any problems.

Hope this helps. Regards, Rex from Oz.


#4

I have to agree with Rex from Oz, especially as far as carefully made
settings and cushioning is concerned. Many mexicans use various soft
bearings to cushion the more brittle mexican opal, I have found sawdust,
cardboard and layered newspaper, also pitch and several substances I
couldn’t readily identify being used. I’ve used a soft plastic such as
pvc, layered seems to work well also a piece of unravelled nylon twine
which is heat joined into a loop. I have yet to try gasket compound
though.

One other suggestion that completely removes the possibility of stress on
the stone is rear setting. The bezel is made and fiinished then the stone
simply pushes in from behind and a locking ring clipped into place with
maybe a few graver curls to lock everything down, claws and rings work
equally as well, but the locking ring removes the chance of damaging an
opal by slipping whilst pushing anything. I have also heard of foil
setting which involves pushing foil around the bezelled stone until it is
firmly gripped. I haven’t tried this.
Anthony L. Lloyd-Rees,

http://www.opalsinthebag.com

 Vancouver B.C. CANADA

#5

One other suggestion that completely removes the possibility of stress
on the stone is rear setting

There was an article in the Lapidary Journal a few years back by Paul
Downing, the opal expert. He advised mounting from the back and
cushioning the stone by bedding it in epoxy. This way the shoulder of the
stone is protected from bumps. The article should still be available.

HTH,
Roy Hot in Tennessee


#6

Roy, how does this differ from glueing it? Do you make a blob of epoxy,
allow it to dry, and then trim it to size?

Marilyn Smith ICQ # 9529587
Decent weather for a change in. . .
Indiana, USA, east of the Mississippi and west of the Appalachians


#7

how does this differ from glueing it? Do you make a blob of epoxy,
allow it to dry, and then trim it to size?

If I remember right from Paul Downing’s article, he made a bezel in which
you mount from the back, about like the coin rings you commonly see, only
shaped to the free form opal (the only way to cut it to save weight and
fire). He worked in wax, then cast. When the mounting was ready for the
stone, he appied a bead of epoxy to the bearing surface where the front
and edge of the opal will contact the mounting. I suppose you might have
to trim this after it sets up and cures so that the thickness is about
uniform and so t hat the epoxy doesn’t show from the front of the
mounting. Then prongs are slid over the opal from the back and the opal
is only contacted by the cushion of epoxy from the front and edge. You
could also slide the prongs over from the side so that you are not pushing
at right angles to the opal surface, and if you want to be really safe,
use the old Emerald setter’s trick and don’t push the prong all the way
down onto the stone, just put a dab of epoxy under the prong. OK, guys,
now wait a minute, I would NEVER, NEVER do this with anything but an opal
or an emerald, but they are fragile. In the case of the opal (expensive
opal) this gives pretty good protection to it and doesn’t show. explain
to your customer why you do this. The worst that can happen is that
eventually you lose the glue and the thing has to be remounted. Meanwhile
the stone is protected and may make it to a remount in 20 yrs.

HTH,
Roy (Jess)