Opal Discoloration--14K wire disintegrates

Jewelry Discussion
1

'Been in the business 15 years and never seen anything like this
(and boy, oh boy, do we need advice :(!!!

53.5 carat, 32 X 25mm, huge, thick, high domed opal. Customer
paid $1200 years ago, had a recent appraisal of over $5000.
Stone appears (appearED) to be Australian white with tons of pin
fire–but the matrix had a pale peachy, pink cast that my husband
and I have NEVER seen before (similar in color to the ryolite
matrix of Mexican opal material, but definitely not mexican
opal) . We surmised the stone had been “Opticoned” and the
customer said she also thought the stone had been “coated” with
something. However the appraisal mentioned nothing concerning
coating or treatment (great appraiser, huh? ) And
we’ve never seen Opticon change the hue of a stone.

I set the stone using 14K wire, polished it with red rouge
(being very careful not allow rouge on stone) threw it in the
dish (full of warm water with a squirt of Joy) with the other
pieces I had just polished, took it to the sink, pulled it out of
the dish and… Oh My God, the stone was like medium orange and
you could barely see the fire of the opal at all. Immediately I
filled a container with 4 cups of warm water and about 3
tablespoons of bleach and started dipping the stone and softly
scrubbing with a toothbrush. Well this caused a tyedye looking
stone, parts going almost white, some staying orange, and others
somewhere inbetween. About this time, I heard what sounded like
wire breaking, so I looked closely and right before my eyes, the
14K wire started breaking where I had made bends with the pliers.
So, I rinsed it thoroughly and set it on a paper towel. In the
next 15 minutes, the wire broke spontaneously in over 15
different places - Oh My God Again.

I removed the stone from the setting and hit it with some
Fabulustre on a muslin buff - Oh now that’s interesting, the
stone “absorbed” the Fabulustre and now has these white splotches
atop the tyedye - what a nightmare.

I’m guessing this baby must have been sugar/sulphuric acid
treated? Maybe that’s what caused the wires to break
spontaneously? I’ve set and wrapped and Rick has cut Australian,
Mexican, Spencer, and other types of opal (probably over 500
stones). A few times I have discolored opal using rouge, and a
little bit of bleach in a lot of water always did the trick
before. But this is a mess and I’m not sure what to do. I
haven’t contacted the customer yet.

My first instinct was to put it in “Attack” (the solution that
removes Opticon), but if this opal’s been sugar/acid treated,
don’t I run the risk of it disintegrating the opal? I’ve seen
sugar treated opals just crumble away in an ultrasound. Is there
anything we can do to save this opal, and what happened to the
14K wire that caused it to break spontaneously in so many places?

Any and all advice gladly received! Help, help, help! Rick and
Kristi Stutt

Part 2

My original letter hasn’t even posted back to my email yet, but
there’s been quite a change in the opal in the last 2 hours!

It is almost 100% back to it’s original color - go figure! This
is unbelievable.

Also, I’ve carefully examined the 14K wire. First, it was from
Tripps (a source that I have dealt with for years), so I’m pretty
sure there was no problem with the original wire. Second, the
only place the wire broke (disintegrated is more like it) is
where the wire came into contact with the actual opal. I’m
guessing that somehow the sulphuric acid they use during the
sugar treating somehow interacted with the mild bleach solution
to cause the wire to disintegrate (?). The opal itself was
intensely discolored after only approx. 7-8 minutes in mild soapy
water and the weak bleach solution seemed to make no difference
to the opal. So now there’s the issue of $$$.

If I return the opal in it’s original form, explaining what
happened, how, and maybe why (if y’all could help me figure this
out), then there’s still the issue of approx $100 worth of 14K
('not even thinking of recouping labor - at this point I’m pretty
sure the lady would have told me her opal was treated if she had
known it). I’d love to offer to mount it again, as this was to
be a very special present for her daughter, but dare I even
offer? (If the thing were to ever come into contact with water or
bleach it might disintegrate the mounting again, right?)

Again, any all advice and experiences gladly heard!

Respectfully,

Kristi and Rick

2

Kristi and Rick, My first inclination is to count your blessings
that the stone returned to its original color, and explain to
the customer that there were problems in setting and, in spite of
an oulay of expense, on your part, that you would rather not
continue to risk damaging her stone. I know the urge to recoup
the cost of your metal is great, but think of the expense of
trying to replace such a stone. Incidentally, these types of
damage claims almost always become priceless heirlooms when they
are damaged or missing. Fortunately, there is an “appraisal” to
rely on. Curtis

3

Some opals that I have worked with, notably the "Peruvian Blue"
type, will change color when soaked in water. They will return to
their original color when they have thoroughly dried out. Changes
additionally, seem to be an increase in translucency in most of
them. Try placing the stone in clean water overnight, and see if
it changes again. I have no idea why your wire broke, but I bet
one of our other compadres does.

Lisa,(a customer just asked for work in 22k, I’ll be asking for
advice soon…) Topanga, CA USA

4

Hello Rick, Iv’e had this happen with opal from vigin valley,
which normally I would’nt touch with a 10 foot pole.A woman
brought me a jar full and wanted one stone out of it and I could
have the rest, could’nt even get her onestone.Anyway, there were
several pieces that did as you said as I started to cut them the
fire diminished to almost nothing and the base color got washed
out look.some would return to normal after a few days, others it
took as much as six months.I cut nothing but opal and I’ve never
seen this before.
good luck, Mike
I’d go into this more but, god, I hate to type.

5

First of all you need to tell the customer as soon as possible.
Otherwise she is going to think you did something to her stone.
Secondly I would recommend you get her permission to send it to
the GIA for analysis. I have never heard of a treated opal
bleeding out acid and I have worked with quite a few opals, a
number of which were treated in the fashion you refer to. Of
course in today’s marketplace anything is possible. It is also
concievable that what you have there is a synthetic opal that is
behaving peculiarly but again you need to get it to a good trade
lab for analysis. As for your $100 if you didn’t warn the lady
at the beginning of the risk associated with working on opals
(which all of you should do all the time out there–for your own
protection!) then you will probably have to eat the loss. Hey
you can always scrap it.

6

Kristi and Rick,

I'm game...  I'm guessing that you have a piece of hydrophane

opal. Though most hydrophane I’ve seen actually looks better
when wet. As to it’s place of origin… could be anywhere.
Here in Oregon at Opal Butte, hydrophane opal is fairly common.
I have hydrophane from mexico. The best way to tell is to touch
your tongue to it. If your tongue sticks to it, it’s
hydrophane. Not sure about the wire breaking (Maybe hydrophane
expands as it soaks up water? Or a chemical reaction?)… I’m
not much help there. I’m sure there are others more qualified
than me to help you… Just couldn’t resist playing the guessing
game! Regardless of whether or not my guess is correct, I’d be
for finding that appraiser and having them take a closer look at
it… A $5000 opal shouldn’t behave that way. Good luck with
your problem stone.

Mark Williams in Oregon

7

I think you have hit the problem on the head. The opal sounds
as if it were treated with sugar and sulfuric acid. The acid
would be the reason the wires broke. You must have caused the
acid to become active by warming and wetting it. The contact
with the cleaning solution was brief and the moisture evaporated,
allowing the stone to stabilize and return to its initial
appearance. I have seen very few actual opals treated this way,
this is usually the treatment for “matrix opal”. This may be a
form of matrix opal.

You might try posting this very interesting (but awful to
experience) situation on the Lapidary Digest
(Lapidary@mindspring.com with the words Subscribe Digest in the
“subject” line to join). As it happens, the digest has a long
thread running right now on opal. If Hale Sweeny (the list
moderator) and the group can’t help, I’d get the stone back to
the owner while it still looks like opal.

John McLaughlin
jmclaughlin@supreme.sp.state.az.us

8

Peter and Cameron,

Whew, many thanks for your timely, informative, and thorough
replies.

We checked OPAL Identification and Value, by Paul Downing Ph.D.
and (oooh, I don’t think I can directly quote the book without
infringing copyright?)…Anyway, this is definitely a hydrophane
opal, probably dyed with a polymer as it is very “light” for its
huge size, and very “hard”. It doesn’t feel or weigh like opal
at all.

I’ll be taking a few pictures of the stone and mounting (or
what’s left of the mounting, now that it’s “popped”) I’d love to
forward them to you for examination and introspection (let me
know if that’s ok). Oddly, the wire didn’t break in the places
that had the most “bends”. That would always be the bail and
bail decorations (in this case, twelve, tight little Victorian
rosebud spirals shaped into a double a fleur-de-lis - now that
is some stressed out wire!) But it broke nowhere except around
the stone. I have mounted 50-60 opal pendants and I can
guarantee you, the wire was not pulled tight around the opal. I
shaped the mounting using a paper/pencil outline of the stone,
then left “almost enough room to stick your finger” between the
top of the opal and the beginning of the bail. Then bent out the
"securing wires" around the opal, front and back.

The mounting was 7 wires of 21 gauge square “thick”. In one
place, all 7 wires broke and 5 of them had never even been bent.
(OK, 3 of those 5 were twisted, but they all broke in the same
place, twisted or not.) Too wierd.

Anyway, thank you again for your assistance in figuring all this
out. It has been an incredible learning experience for me (and
my husband who is a lapidary - btw, he didn’t like the bleach
idea, but my old bad habits die hard [especially since I learned
that little “trick” from a 87 year old lapidary codger out in AZ

  • bless his soul - his little trick almost cost me $5000] not to
    mention how stupid I feel about a thousand different ways).
    Thanks again for your help, knowledge and interest.

If anybody else would like pix of this mess, just let me know!

Rick and Kristi Stutt

9

Hi Kristi,

This gets a bit long but bear with me ; )

Gotta love opal or hate it (I am of the former type- okay I’m an
addict but I can stop any time - I just don’t want to). Opal is
almost a living stone in the way it reacts to it’s environment.
Opal will absorb water at an startling rate and will change in
form when it does. Hydrophane opal changes typically from milky
to transparent when placed in water. I have seen white opal that
look great when you are cutting the stone and looses all colour
when dry. Mexican jelly/fire opal goes from transparent to opaque
sometimes in minutes when in water. Opal also does not react
well to strong chemicals as it will absorb them and react to them
well after you have thought you have rinsed them off.

With your piece my guess would be a couple of mitigating
factors. One is the opal was treated with some foreign substance.
Some people use hardening oil or resins on it, others Opticon.
The opal ignorant also resort to other witch doctor formulae that
have no real value. Sugar treating is usually done to alter the
colour of the base material. By soaking in sugar then in acid the
base colour is darkened (i.e. turned black) and the play of
colour enhanced. Sugar treating does nothing to stablize the
material and all acid is washed off.

With your stone being white I would say it being acid treated is
not the case. From your description the matrix colour is fairly
normal - usually on white opal it is trimmed off though - and
don’t conclude that the opal comes from Oz. There are several
sources worldwide but the Australian material tends to be the
most stable with regards to moisture.

What happens with coatings is the natural change in water
content now is restricted and because the treatment will
penetrate more in porous areas, less in others you get splotches
(I have seen great variation in the hardness/porosity of opal
across a single stone - makes polishing fun). It is hard to say
what reaction took place to cause the orange colour. My guess
would be a reaction between the opal, coating, and the dish
soap. Given the colour returned to normal after the stone dried I
would say that the material they coated the stone with reacts
with water or perhaps minerals in the matrix - the opal probably
helps by having areas that absorbed more than others. The colour
change is due to water reacting. Ever see a ring left from a
glass on a piece of furniture - much the same idea. Sometimes if
it dries the ring fades other times not.

What to do about your poor misguided stone? Obviously your
clients opal has a thing against water. So don’t soak it - in
anything. You only need to clean the surface. Besides the matrix
and the opal absorb water at different rates and may complain by
cracking. Leave that poor tortured stone alone! Opal is very soft
as well as heat sensitive and most metal polishes are quite
coarse compared to the polishing compounds for stones. Polishing
on a high speed buff with Fabuluster I am suprized you didn’t
wind up with several small pieces. Get some cerium or tin oxide
and apply by hand with a clean soft rag wrapped around a stick.
This will polish the opal nicely with out any of the excitement
you have had so far. I would say it is safe to mount again but
design the mount to allow the stone to grow and shrink and
protect the edges (I froth when I see opals in some chain store -
prong mounted like some cheap chunk of cubic zirconium - sigh).
I haven’t conducted any experiments on how much opal can swell -
may be something I will check into - I know from practical
experience it does though.

How should you clean opal? Well firstly opal should not be
allowed ever to soak in soapy water or any liquid when finished.
The soap penterates the stone and does 2 things. One is it will
swell even more than in plain water (soap reduces surface tension

  • all the better to soak in). Worst thing you can do is wash
    dishes with an opal ring on. Ever wonder why opals seem to loosen
    in their mounts or fracture even in a bezel setting? Secondly
    the stone will discolour from the soap residue in the stone.
    Soaking a finished opal in anything is not a good idea - the
    thought of using a highly reactive material like bleach makes me
    shiver. To clean an opal use plain water or if really grungy with
    oily substances use lacquer thinners. Apply with a q-tip (very
    sparingly if using thinners- let it dry between swipes).

Okay lets change hats here - material sciences anyone? I am
assuming it is solid gold wire not gold filled. Gold is a very
non-reactive metal (okay okay if you ionize at high temperatures
it and etc etc) - doubtful that even concentrated suphuric acid
used in sugar treating would even tarnish it - besides if you
handled the stone and there was anything on it that would react
with gold that way your skin would be gone. So it is not a
chemical thing (just what brand of dishwashing soap was that? -
New Joy with 50% more Hydrofloric acid!). So that leaves
mechanical forces - gold is typically very mallable - so work
hardening shouldn’t be an issue. Did you heat the material or
solder it? This could introduce problems in the structure from
foreign elements. What my guess (without seeing the piece) is
that your funky little opal grew enough to stretch the setting
and the wire failed at the stress risers where you bent the wire.
Even after you removed the opal from the water it would continue
to swell as the internal moisture spread. Please also be aware
opal does not like pressure - it will fracture quite easily so
careful when you form the wire around it.

From the sounds of it you had two separate issues happen at the
same time. Take a deep breath relax and realize the situation is
not that bad - the stone is intact and the same colour (Whew! is
all I can say), your gold scrap is re-meltable, and nobody got
hurt. So I would review my design, think about how to tell the
lady about the stone (gently) and making sure she is aware of the
problem (she might not want to use it in a gift to her daughter
if it is going to behave that way) - maybe suggest a pendant
since they typically don’t get very wet.

Hopes this helps - don’t give up on opal - it is quirky but very
beautiful- I have had beautiful experiences and bad experiences
with it but I still love it.

Cameron Speedie
Island Gem and Rock

10

Hi Kristy and Rick, With reguard to the gold wire mounting, my
best guess is that the clorine bleach reacted with the gold.
Clorine attacks gold. I have seen customers come in with
disolved gold chains from the reaction to clorine.The wire was
probibly thin in some sections? Does this sound correct? Keep me
posted, Don Wollwage

11

About your wire that broke…in re-reading your post, am I
correct that you placed the piece in a mild bleach solution?
Wasn’t there recently a thread about bleach breaking down gold,
and causing prongs to snap off…explode, as it were? I’d go
back and look for that thread.

Good Luck,

Lisa,(The dogs brought me home a nice brace of gophers
today…yeuch!), Topanga, CA USA

12

Your discussion of the problem with the opal is interesting but
I have been working with opals for more than 25 years (and a lot
of opals I might add) and I have never seen or heard of an opal
expanding in size. When liquids are absorbed into opal it is
because it is a porous material. Being porous does not mean it
expands. I would like you to reference some legitimate
gemological literature on this because I don’t believe there is
any way a stone can expand.

13

At the shop where I work we have experiened a condition with
white gold called stress corosion cracking. Customers who work
extensivly with bleach can cause the gold to virtualy
disintegrate.I have seen prongs on white gold prongs literaly
drop off,or break when touched with my finger.With what was
explained about opal expanding this would explain to me why
prongs on opal might have broke and not the bale.To correct the
problem in White gold heads with a customer that works with
bleach we use a palladium white gold head.It has been explained
to me that the alloys of normal White gold and not the gold
itself that reacts to bleach.hope this helps Bob

14

Cameron,

Thanks for the well written dissertation on opal.  The longest

one I’ve read in which I agree with everything! Seems there are
as many opinions on opal care as there are opals. My only
question is: What value would you give an opal such as the one
Kristi’s customer has? I was always under the impression that
hydrophane was pretty worthless except as an interesting
specimen. I’ve carved a few pieces for my own entertainment, but
I wouldn’t dream of selling them. Unless of course, it was to
someone who knew what they were getting and wanted it
because of it’s entertainment value. And that they knew it
could self-destruct at any moment (One of mine has - It was fine
for almost a year - one morning I found it in three pieces - no
apparent reason).

To Kristi:

I would be curious to know how the aftermath of this adventure

runs… How the customer responds to this new I’d
also like to see the pictures!

Mark in Oregon - Where that opal could soak up all kinds of
moisture.

15

Hi Kristi,

I would really like to see some pics of this rogue stone. I
don’t do valuation of stones(except when I am buying them)so this
is mainly just an opalholic’s opinion. With opal a lot of the
value is pretty subjective rather than fact based. I have my
suspicions this stone may be over valued (or the appraiser was
just trying to make the lady happy)given it seems to have been
treated and has some rather psychotic episodes related to water.

I don’t think it is really dyed white but probably stablized
with a polymer or some other goop - makes me really wonder about
the origin and how honest the salesperson was. Some opals are
really light (makes buying by weight less painful). Spencer Opal
volume for volume weighs a lot less then Coober Pedy. Also since
at any given time most normal well adjusted opals (had a good
childhood etc. etc.) has a 6% water content any opal with less
than this will feel light. Also most polymers are lighter than
water so if it is substituing for the normally present water it
will make the stone feel lighter. If it wasn’t a finished (and
alledgely expensive)stone I would heat a piece of fine wire up
and touch the matrix with it briefly - if a pall of smelly
plasticy smoke comes up - well guess what my conclussion about
this being a “natural” opal would be.

Hydrophane exhibits different behaviour and may not retain that
much water therefore it will be lighter still. I have seen some
really nice Spencer solids (especially some of the display pieces
at the store in Spencer)but they tend to check so most people
stablize them. This is one possible source. Some opals have
almost a chalky feel to them and others feel like glass. It might
be an idea to get an official opal expert type opinion from GIA
or someone as to the origin of this stone if you are really
bothered about it.

Hmmmm… Your wire sounds like it has problems of it’s own -
could be a bad batch - have you contacted the supplier yet?
Strange though because gold wire is typically drawn - any
weaknesses like porousity etc. should have shown up there (and
BTW thank you for not abusing your opal when setting it - sad to
say but there seems to be a lot of people making opal jewellry
that don’t understand some of the nuances of the material).
Maybe the wire picked up some bad habits hanging around with that
opal!

Did the little old lapidary have any other bad habits like
recovering gold with mercury or heating stones before polishing
them? Still some people that think the surface of the stone melts

  • like raising the temperature of the stone 2-3% of the melting
    temperature would help anyways even if the surface did melt. Life
    is about learning - don’t feel stupid - thanks for sharing the
    experience.

Take Care,

Cameron Speedie
Island Gem and Rock

16

Kristi, I would be interested in seeing some pics of your
"mess’. I just hope webtv dosnt eat them - (new computer on the
way) Your wire problem may be due to chlorine corrosion, although
it seems to have happend awfully fast. This is a big problem with
jewelry worn in hot tubs or swimming pools, or anywhere chlorine
is (laundry etc.). Possibly your rather concentrated solution
accelerated the reaction? I believe there was a thread on this
problem a couple of months ago - ( or was that on ArtMetal -
humm?) Check the archives.

Anyway, I agree with Cameron’s analysis on the opal question - I
couldn’t have said it better myself. I do have some doubt that a
"treated" hydrophane opal would be worth $5000 but without
having it in hand it would be hard to judge. Oh, and I wouldn’t
worry to much about quoting from Paul’s books as long as you give
credit to the author. Paul is a very nice guy and is truly
interested in educating the public about the coolest stone on
earth!

17

Daniel, Opal is an amorphous silica gel consisting of water and
microscopic spheres of silicon dioxide. Gels can expand and
contract…though I grant you that property isn’t likely to
cause a visible size change in an opal. Strictly speaking,
opal isn’t a stone - as it contains no mineral component. In this
case I’ll vote for the hypothesis that the setting broke because
chlorine bleach attacked the gold alloy. -Pete-

18

Daniel,

I’d agree with you that it’s unlikely the opal would actually
expand due to water absorption.

However, note that when normal opal of a variety with high
levels of hydrations, such as much Mexican or Nevada opal dries
out, it’s common that it’s surface crazes. No surprise to
anyone, right? Keep in mind that opal’s amorphous silica gel
structure is not the same sort of defined, rigid affair that a
true crystal structure would have. The mechanism of that
crazing is a slight generally irreversible shrinkage as the
silica gel structure of the opal looses water and
compacts/shrinks. If it did not do so, there would be no stress
buildup from dehydration to crack the surface. The surface does
craze, however, because that drier layer at the surface has
shrunk, and no longer “fits” around the inner portions, creating
stress that cracks the opal. But even here, the actual
dimensional change is likely to be virtually undetectible, and
certainly not enough to affect a metal mounting surrounding the
stones. Perhaps a key feature of hydrophane opal is that it is
able to dry out WITHOUT this shrinkage taking place, leaving the
pores still open enough to again take up the lost water…

Peter Rowe G.G.

19

Peter, I can accept what you are saying here. I think however
the reason that there may seem to be enough shrinkage for it to
impact the setting is that as opal is such a soft material, and
wearing away of the surface of the stone is so common, that
perhaps this is what is happening and being perceived as
"shrinkage".

20

Hi Daniel,

I mainly based my observations on opals that display a high
degree of instability such as Mexican jelly (fire), Spencer
white, and to a degree low grade Australian white. When I said
the opal may have swelled I didn’t mean like a balloon (and no I
don’t think all opals display this property). If a stone is set
very tightly and one element of the piece (stone or setting)
displays even a little expansion and neither material is
compressable then you will get strain. The movement may be small
but will cause considerable forces to occur.

When I originally replied I said I had based my comments on my
experiences (empirical) rather than laboratory based
If you have time to chase down an article please do (this is sort
of the realm of chemistry types so you might want to start a
search in that area) - but I as a lowly lapidary have stones to
grind and I’m willing to settle for calling it an opinion rather
than a scientific paper. Besides not everything is in books yet -
otherwise research would be a dead field. I too would like to
see a study of this phenomena of (alledged) hydrotrophism (there
probably is one - under a different name). It definately would
give a better understanding to some of the behaviours of opal. I
think it would be very cumbersome to come up with a methodology
given the variation of physical characteristics of opal and
achieving a predictable hydrostatic distribution within a
laboratory setting in order to satisfy the scientific criteria of
repeatability.

To qualify my opinion on opal moving:

  1. Some opal displays an annoying tendency to craze or crack
    when it is dried or wetted - this behaviour is because a moisture
    differential between the different parts of the stone causes
    strain. The only way for this to occur is for the elements to
    have moved (in a simplistic sense- I could get into a longer
    discussion but I would have to blow the dust off several
    mechanics of materials texts). I believe that the Australians
    have a standard regarding whether or not it is suitable for
    market based on this hydro-stablity and this is also why some
    very beautiful material such as Virgin Valley opal is usually
    destined for display specimens. The majority of material sold for
    gemstone cutting is quite stable. If the material was not stable
    it soon would not be selling well.

  2. From practical experience - I have set jelly opal in to
    pieces, the setting has been done properly etc., well when the
    weather gets nicer (Victoria is in the Pacific Northwest - We get
    a broad range of humidities) the stone gets loose, when things
    get damper it tightens up. Given that the differential of the
    co-efficent of thermal expansion for opal and silver (I don’t
    have it for opal so I am assuming a little) are not that great
    for the range of temperatures up here - I am left to think that
    either the stone (hydrotrophic) or the silver (inert) has
    changed.

  3. Hydrophane opal changes its optical charteristics on exposure
    to water. My understanding of how precious opal works is that the
    tiny spheres that make up opal are arranged so that light
    bouncing off them forms the fire (If you want more depth - Simon
    & Schuster’s Guide to Gems and Precious Stones pg. 30 gives an
    easy to digest explaination). The difference between (besides the
    price) of precious opal and common opal is in how these spheres
    bounce the light around. Since there is a definite change in the
    way some hydrophane material looks when wetted, as described by
    Kristi (i.e. opalescence/lack off), and I can’t attribute it
    soley to the water changing the optics, I am left to think that
    some how the spheres are moved around enough to cause fire to
    appear. I realize that the movement probably isn’t large but
    enough for me.

  4. Opal is composed of very tiny spheres that form bonds between
    each other. The reason that it is porous is the gaps between the
    spheres are spaces filled with a gel and spaces (Schumann -
    Gemstones of the World pg. 150 - hey it was handy). Water is a
    very interesting fluid, I believe it is known as a universal
    solvent as it has the ablity to disolve or weaken bonds or make
    gels swell. I don’t have a degree in chemistry but this might
    have some effect on some opals (all you people looking for a
    master’s disertation - Hydrotropic Characteristics of Non-typical
    SiO2nH20).

So that is my opinion - if you still don’t believe stones can
move then I am going to have a heck of a time getting my stones
off the dop stick by sticking them in the freezer to take
advantage of the differences in expansion between wax and rock
(arguably a different causitive agent for movement - but thought
it might make you believe).

Cameron Speedie
Island Gem and Rock