Cleaning Opals

Why and how does glycerin “suck the water out of opals”?? I have
never heard of that before, and in fact was advised many years ago
by a jeweler, to keep my opals in glycerine when I was not wearing
them. Is that wrong, and if so, what would you recommend, distilled
water only, or is it necessary to keep them in liquid at all? Thanks
in advance. Courtenay

One reason glycerin is used is that the refractive index of opal and
glycerine is very close and therefore if there are any fractures in
the opal they will remain undetected. “Suckingthe water out” is a
new one to me. Kevin

    Why and how does glycerin "suck the water out of opals"?? I
have never heard of that before, and in fact was advised many years
ago by a jeweler, to keep my opals in glycerine when I was not
wearing them. Is that wrong, and if so, what would you recommend,
distilled water only, or is it necessary to keep them in liquid at
all? Thanks in advance. Courtenay 

There are lots of different opinions about this! I, too, had never
heard that opinion about glycerin. In fact, in Australia at least,
glycerin is what is normally recommended. Len Cram , after all his
experiments told me glycerin, and says not to use water! On the
other hand, logic seems to say water! think that probably what it
comes down to is to preserve the water that is in the opal. (And
this is what the glycerin is supposed to do.)

Margaret

I’ve been following the discussion about opals and glycerin vs.
mineral oil. About 20 years ago, we bought a peach-colored precious
fire opal from a vendor in Cancun, Mexico. The vendor had hundreds
of cabochons in a variety of stones, but only two same size large
opals. We selected a pendant setting and returned the next day to
pick it up. It was beautiful. However, at the hotel an hour later,
all of the play of color was gone and the stone felt oily. When
placed in water, all of the flash colors returned, but disappe ared
again within minutes out of the water. The next day we returned to
the vendor to show him the stone. After much discussion (in
Spanish) with the person who set the stone, we were told the setter
used mineral oil to push the stone into the setting. The vendor
exchanged the damaged stone for the good one. The original Orchid
comment was that the person didn’t know if the opal was in glycerin
or mineral oil, but that the opal flash was still there. Does this
mean that it is glycerin rather than the mineral oil (which caused
our stone to lose its flash)? Just curious.

Nancy