Working with opals

Jewelry Discussion
1

Hi my name is rebecca ziersch. I am a jeweller and have recently
found a new job working with opals. However this is an area i need
to learn about. I know that opals need to be kept moist, and
shouldn’t be exposed to heat. But i was wondering what the effect of
methylated spirits would be on an opal stone. Although i haven’t
found any conclusive answers to this, i would assume that this would
be a bad idea.

The reason i ask, is that when i usually set my stones, i secure the
piece sticking it onto a shellack stick while pushing over the bezel
or claws. But to take the piece of the shellack it needs to be
heated slightly, and then soaked in methylated spirits to remove the
shellack.

So basically, my question is, can i use shellack to secure an piece
to be set with opals? Will using metho affect the opal? Is there
another way to remove the shellack instead of metho? If i can’t use
any of these methods, how do i secure a piece to be set with opals?
If you have any solutions, please let me know. you can contact me on:
@Rebecca_Ziersch

thank you very much,
kind regards,
rebecca.

2

Rebecca,

For short periods, such as cleaning off wax or crud, I often put
opals in acetone, metho, denatured alcohol, etc, with no damage
whatsoever. In your case, however, I would be more concerned about
the use of heat to remove from the shellack stick! Opals do not like
heat and while there are proper ways to gently heat opals, any open
flame is likely to craze the stone. When dopping opals for cutting, I
learned many years ago, to place them in a shallow can of water and
then gently heat it with an alcohol lamp. When the water is warm, the
opals are warm and can be safely removed for dopping. You might try
the same thing to remove them from the shellack.

Cheers from Don at The Charles Belle Studio in SOFL where simple
elegance IS fine jewelry! @coralnut2

3 
    So basically, my question is, can i use shellack to secure an
piece to be set with opals? Will using metho affect the opal?

Yes to the first question, no to the second. The answer is that the
effects of the shellac and methylated spirits over such a short term
will not likely affect opal. Just don’t soak it in the spirits for a
long period, and be meticulous about removing all of it from the
gem.

Opal does contain water, but it is typically only 3% to 10%, more or
less. And while it is called “porous” it isn’t like a kitchen
sponge, either. It’s still a rock that can absorb liquids, but it
isn’t like you can squeeze it and sop up the fluid that spurted out
of an LPG tank. It takes a lot more time than cleaning shellac with
spirits would take. Have fun setting your opals :slight_smile:

James in SoFl

4

If you want to learn about working with opals, I highly recommend
Paul Downing’s books.

Opal: Advanced Cutting & Setting
By Paul B. Downing

Price: $13.56

…

Opal Cutting Made Easy (Jewelry Crafts)
By Paul B. Downing

Price: $8.95

…

Opal Identification & Value
By Paul B. Downing

Price: $42.46