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Incorporating opal


#1

Was: Incorporating tanzanite

On the other hand, opal isn't good for rings either but that hasn't
stopped my customers from wanting it in rings (which I sell to them
with a whole potful of warnings).

Given your long years in working jewelry and your business acumen
shown in your posts to Orchid, I’m surprised at your statement “opal
isn’t good for rings”.

Everything in these matters depend on appropriate design for either
opal or tanzanite or indeed any stone.

I’m curious as to what “a whole pot full of warnings” would contain.
Or perhaps your post refers to the recent topic “No longer desire
client patronage”.

While I’m on the topic Derek’s statement has no basis in fact to
warrant a blanket statement such as this: “Only a few stones crack
spontaneously, like opal, that can be unstable”

KPK


#2

Kevin,

Opal isn’t good for rings because it is a fragile stone and will
most assuredly break if whacked hard, which most rings often are. It
doesn’t matter what type of setting it is in. Whack it, it breaks.
Same goes for tanzanite and many emeralds. Granted if you whack a
diamond the right way it will break too but it won’t happen with the
regularity of opal and tanzanite. I suppose if you bezel set the
stones and then built up some huge protective barrier around them,
you could say that it is an appropriate design for the stones given
their durability. Then the question becomes is it a

  1. practical,
  2. attractive and
  3. functional design?

Bezels alone do not protect these stones, so I’m not sure what you
mean by “appropriate designs”. What do I mean by a whole potful of
warnings? I tell the customer that

  1. the stones are fragile and will break if whacked,
  2. I take no responsibility for their whacking and breaking them,
  3. I take no responsibility for scratches, nicks, dings, etc. and
  4. that if they aren’t exceedingly careful with them they will break.

I can also tell you that I have some customers with opal rings of
mine that they have worn every day for years and the opals are still
in pretty decent shape. I also have customers with opal rings that
look trucks ran over them. And I have customers who have broken the
stones. In terms of numbers, I have far more customers with opals
that look like trucks ran over them or broke them, than any other
stone I sell. My telling customers that certain stones will not meet
their lifestyles does not in any way mean I am turning them away as
customers. If they choose to find someone else who will do what they
want without all the warnings, more power to them. And when they
break the things they can go back and complain to them. I, for one,
will not end up like Fred Ward and lose my whole jewelry business
because some customer didn’t listen to me, whacked a fragile stone
and then had an insurance company sue the jeweler over the state of
the stone before, during and after the whacking. (And anyone in the
business who doesn’t know about this story would be well advised to
go out and research it before they go selling any expensive emeralds
to clients.)

As for Derek’s statement (which I missed actually), perhaps he was
referring to the habit of opals crazing over time. While you might
not call this spontaneous cracking, it certainly is something that
happens over time to opal without any stresses from wear and tear,
and most assuredly reduces the value of the opals to just about nil.

Daniel R. Spirer, G.G.
Daniel R. Spirer Jewelers, LLC
1780 Massachusetts Ave.
Cambrige, MA 02140
www.spirerjewelers.com


#3

My response to Derek’s statement and yours since you choose to
answer for him:

I have been cutting opal and setting it for more than thirty years
and to this point have not witnessed an opal spontaneously craze.

There are few stones that when ‘wacked’ will not be broken or
seriously damaged. Some people wear their jewelry comfortably and
some will wear their jewelry while repairing machinery.

Your bias concerning opal based on your experience is not sufficient
to extrapolate your experience into a blanket statement.

As to the Fred Ward incident: when hundreds of thousands of dollars
are involved there will be litigation. I respect your business sense
but the inclusion of the “Fred Ward” case in this discussion is a bit
over the top.

KPK


#4
I, for one, will not end up like Fred Ward and lose my whole
jewelry business because some customer didn't listen to me, whacked
a fragile stone and then had an insurance company sue the jeweler
over the state of the stone before, during and after the whacking. 

Wow, what a horrible incident!!! I found an article by Fred Ward
here on Ganoksin:

http://www.ganoksin.com/borisat/nenam/emerald-case-intro.htm

It certainly gives one food for thought. It’s a shame that there are
such people as his customer in this world who are so dishonest that
they can abuse a beautiful piece of jewellery and then turn round
and blame it all on the jeweller who made it for her. How do people
like that sleep at night?!

Helen
UK


#5
While I'm on the topic Derek's statement has no basis in fact to
warrant a blanket statement such as this: "Only a few stones crack
spontaneously, like opal, that can be unstable" 

Opal can indeed surprise the unwary: a few years back I gave my wife
a fairly large Australian Coober Pedy opal that I had set as a
pendant in gold. It was perfectly sound, apart from some slight
inclusions of sand. I found recently when I looked at after 35 years
in her jewelry box that it had developed numerous cracks throughout.
Other opals from Coober Pedy, Andamooka, and Lightning Ridge that had
been in the same box for just as long were not affected at all!

Of the many Australian and Mexican opals that I have cut and
polished, very few have self-destructed like that. This instance
would appear to warrant the statement that it had cracked
"spontaneously."

My 2 cents.
Dick Davies


#6

Speaking of opals, my ex-husband’s mother has asked me to mount an
old opal for her. It was the central stone of her engagement ring
which came from London’s Garrard’s Jewellers in the 1950’s. The ring
had diamond side stones. Years later the opal fell out of the ring
and whilst living in South Africa, their maid stole a number of
jewellery items, including the gold mount with diamonds - so now all
she has left is the opal. She’d like it mounted in either a ring or a
pendant.

The opal in question is very dull looking and as such isn’t suitable
to be mounted in anything at the moment. I have a few opals that
I’ve bought recently and they have a much better finish (as you’d
expect) and this particular opal has lost its polish, compromising
its colour play (the polish and colour play on the cab’s flat back
are much better than on its domed front). Can its surface be
refinished easily, ie by myself, thus not incurring any extra costs?
I don’t have any lapidary equipment but have some of the usual
jewellery polishes and wondered if I could load a cloth with one of
them and restore the surface that way? I have the usual things like
Fabulustre and jeweller’s rouge and also have platinum white and
platinum blue polishes.

As for remounting, I’m toying with the idea of buying a suitable
mount rather than making one. The prices for ready-cast ring mounts
seem to be cheaper than me buying the appropriate gold and
fabricating one myself.

Any opinions (apart from “don’t do it!”) and/or advice would be most
welcome, thanks.

Helen
UK
http://www.hillsgems.co.uk


#7

Kevin,

I too have been cutting opal for quite a few years, and yes, I have
had them spontaneously craze. One memorable one was a Mexican fire
opal that I had faceted to a roughly 2 carat emerald cut. I had put
it in a gem case immediately after finishing it, where it stayed,
untouched, for I don’t know how many months, probably more than six
and less than a year.

Next time I did look at it there was a pronounced sickle shaped
crack in the pavilion that had not been there before, and, even more
singular, in the cusp of the sickle was a milky white cloud. One
could argue that the crack might have already been there, too minute
to see, but certainly that white cloud was NOT in the stone to begin
with.

I have also seen Ethiopian opal spontaneously crack. At Tucson last
year I met up with two Ethiopian dealers & did quite a bit of cutting
& instruction for them, say about forty or fifty stones. Of these,
several crystal opals (the glass-transparent type) developed
spontaneous cracks within a day or two after finishing. Again, one
could argue that the cracks had been there already, too small to see.

Two personal observations may be of interest for anyone working
Ethiopian opal. One, of the stones I cut, the transparent ones were
by far more susceptible to spontaneous cracking; the dark base,
chocolate colored ones stayed sound. Second, hot wax dopping the
transparent ones infallibly cracked them; the chocolate base stones
remained unaffected.

These are special cases; Australian opal (generally) is much more
reliable. But some from the Mintabie field contains minute interior
cracks which may not be immediately apparent and may grow. Further,
as far as I know there have been no significant new opal discoveries
in Australia in about the past decade (Christine Roussel, correct me
if I am wrong???) - so it seems quite likely we’ll be seeing more and
more of the Ethiopian material in the next few years.

Cheers,
Hans Durstling
Moncton, Canada


#8
There are few stones that when 'wacked' will not be broken or
seriously damaged. Some people wear their jewelry comfortably and
some will wear their jewelry while repairing machinery. 

I wanted to take a part in this discussion before, but nuclear war
on another thread kept me busy.

I am in complete agreement with Kevin. First there are different
kinds of opals, some better than others. Most problems associated
with what is called CT-opal type, but I want to address the subject
of setting opals which was touched in the previous posts.

Opals are fragile, there is no argument about it, but consider this:
Porcelain tiles are fragile too, but we tile our kitchen floors with
them, and if mounted properly they can take a hit.

When mounting opals, the setting must not allow any movement of the
stone, and must be massive. If fragile material prevented from
flexing and moving while hit, it will not crack. That is why kitchen
tiles, as fragile as they are, can survive when something heavy
dropped on them.

Leonid Surpin
www.studioarete.com


#9

Hans -

You’ve expanded this thread to another dimension. These are anecdotes
that are very interesting but beyond the scope of this thread; which
I
took to be the interaction between jeweler and customer.

In normal jewelry one rarely sees mexican opal and I would venture to
say “Ethiopian” opal never. These are exotics that only opal 'freaks’
like you and me would be interested in. Mexican opal dealers leave
their rough on the roof for a year to see what happens before they
grade the material. Not all do that; but I’ve heard that about
dealers in Queretaro; I personally do not know if this is factual.

Ethiopian is new and untested and I would say offered by people out
for quick money. I have seen Ethiopian that is breathtaking. But, at
wholesale a stone a cab between 25 & 30 mm was $5000 wholesale.

Above all, “trust the dealer”; but then, who do you trust? I’ve spent
years cultivating opal dealers and I’ve had to ‘eat it’ more times
than I like to admit to. I always am interested in new sources; new
material that I haven’t seen before. But I have to be convinced of
it’s worth. I still get burned on occasion.

Opal has very special qualities unlike any other stone which leads
people to project fantasies and forget common sense.

To get the best takes more than money and lots of money; but above
all finding those dealers that one can trust. Opal comes in many
grades and there is some really low grade material that could
spontaneously do almost anything.

A friend and dealer whose company has been in the opal business for
more than one hundred years takes the long view. He’s told me that he
has bought opal rough which he then sets aside for at least a year
before he examines it for quality. His company’s reputation is
everything. There are newer people who aren’t so fastidious; and once
they’ve sold you material hope to not see you again.

For those who go to Tucson beware. There is always the latest, newest
material that should be approached with great suspicion. There are
predators waiting.

KPK


#10

Kevin,

I can’t say that I have seen opal spontaneously (i.e. immediately as
I’m watching it) craze, but I have seen plenty of old pieces with
crazed opal in them. Not broken, not chipped, just crazed throughout
the stone and it wasn’t from wear and tear. Actually I’ve seen pieces
that sat in vaults for most of their lives and were crazed
throughout.

I’m also a bit befuddled here. The fact (and this is based on what
every gemological study of opal I’ve ever seen says) of the matter is
that opal is a softer, more fragile material than most gem materials
out there. It does break more easily than other materials and it
certainly scratches more easily. So when you say:

Your bias concerning opal based on your experience is not
sufficient to extrapolate your experience into a blanket statement

I am completely confused. Are you telling me that all of the
literature on the durability of opal is wrong?

As for the Fred Ward case, the original sale price of the piece was
well under hundreds of thousands of dollars (I believe it was in the
$30,000 range). It put him out of business, however because triple
damages were awarded and he had to pay all of the legal fees. That is
what got it up into the hundreds of thousands, not the cost of the
piece itself. In view of the fact that there are many opals out there
being sold in the $10-30,000 range (and higher) I would say that this
is an appropriate reference point. Everyone likes to say it can’t
happen to me, until the day it does.

Please don’t get me wrong here. I love opal. I’ve always sold lots
of it. And I’ve sold some extremely expensive pieces of it over the
years. But the reality of its durability and long term wear issues
have to be explained in great detail to the customer so that no one
(neither you nor the customer) gets screwed in the long run.

Daniel R. Spirer, G.G.
Daniel R. Spirer Jewelers, LLC
1780 Massachusetts Ave.
Cambrige, MA 02140
www.spirerjewelers.com


#11

Helen.

If the surface of the opal is not pitted, you can polish it using
"gris de paris" then “vert de paris” - which are polishes for eg
steel and platinum.

please, please be aware that the opal will become hot. this is not
good for opals with even slight flaws. keep it cool with water. and
please be aware that this is in no way, as far as I know, a
conventional way to polish opal. But I have recently been enjoying
working with opal without any conventional lapidary equipment and
these are the final steps that I use to get a high shine, glassy
finish.

caveats apply. your mileafe may vary. etc etc etc. :wink:

http://duckduckgoosestuff.co.uk/duckduckBLOG/?p=21


#12

Hi Kevin,

I have been cutting opal and setting it for more than thirty years
and to this point have not witnessed an opal spontaneously craze. 

I haven’t been cutting opal for any years, let alone thirty :-), but
I have seen it spontaneously craze. The Coober-Pedy material I
often use is especially prone to this though I’ve seen it (more
rarely) with boulder opal.

It is a fact that opal is likely to craze at some point but it’s
true that the more stable material may last considerably longer than
a lifetime. The problem for those of us who create with it (and/or
wear it) is that you can’t tell how stable a stone is from looking at
it, though material from some localities is more dependable than that
from others.

The potential instability of opal doesn’t stop me from designing
with it however; I love the stuff!

Beth


#13

Kevin.

Ya know, this subject comes up periodically and we seem to get the
same hees and haws over and over. You have been cutting them for
more than thirty years and not had one craze???!!! Well, I’ve also
been cutting for nearly 40 years and guess what? Yeah…I’ve had a
number of stones just craze up. In fact, recently a client brought me
a beautiful coober-pedy stone cut as a pear…about 40mm long and 17
wide at the bulb. She had it for nearly 25 years and…well the
entire point down nearly 10mm had just broken off. I checked the
setting and it was tight and well done as were the 21 diamonds
around it. This was a VERY bright and well cut stone but that, of
course, has little to do with it’s integrety. When I took a good look
at it, the stone was crazed through and through! Was it like that
when she bought it? I don’t think so…it came from a well known
source.

Once again, I reiterate my oft stated opinion…if you wait long
enough, all opal will craze. Maybe you just haven’t waited long
enough yet Kevin~!!

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


#14
I can't say that I have seen opal spontaneously (i.e. immediately
as I'm watching it) craze, but I have seen plenty of old pieces
with crazed opal in them. Not broken, not chipped, just crazed
throughout the stone and it wasn't from wear and tear. Actually
I've seen pieces that sat in vaults for most of their lives and were
crazed throughout. 

Opals contains as much 5% to 8% of water on average. Some varieties
can go as high as 20%. If opal improperly stored or exposed to strong
light, water dries out and opal become crazed. The higher water
content, the more unstable the material is.

Leonid Surpin
www.studioarete.com


#15
I can't say that I have seen opal spontaneously (i.e. immediately
as I'm watching it) craze, but I have seen plenty of old pieces
with crazed opal in them. Not broken, not chipped, just crazed
throughout the stone and it wasn't from wear and tear. Actually
I've seen pieces that sat in vaults for most of their lives and were
crazed throughout. 

I have been to the Smithsonian’s collection and almost every opal
they exhibit is crazed. Also much of the info they provide is
incorrect. I have no idea why that’s the case.

I am completely confused. Are you telling me that all of the
literature on the durability of opal is wrong? 

I would say that just because something is in print does not make it
true. I was asking about your personal experience; the rest is
hearsay.

Another point, there are probably over ninety varieties of opal from
Australia alone. They don’t all exhibit the same properties.

As for the Fred Ward case, the original sale price of the piece was
well under hundreds of thousands of dollars (I believe it was in
the $30,000 range). It put him out of business, however because
triple damages were awarded and he had to pay all of the legal
fees. That is what got it up into the hundreds of thousands, not the
cost of the piece itself. In view of the fact that there are many
opals out there being sold in the $10-30,000 range (and higher) I
would say that this is an appropriate reference point. Everyone
likes to say it can't happen to me, until the day it does. 

Daniel you’re dealing at a level much higher than most of us will
ever experience; thus my specific comment. Not that it’s not
interesting.

Please don't get me wrong here. I love opal. I've always sold lots
of it. And I've sold some extremely expensive pieces of it over the
years. But the reality of its durability and long term wear issues
have to be explained in great detail to the customer so that no one
(neither you nor the customer) gets screwed in the long run. 

I understand your taking time to explain to customers the necessary
cautions of what they may be purchasing.

I spend a lot of time with customers explaining and I’m very careful
in my designs for opal jewelry making sure the designs are
appropriate. I don’t want to discourage a purchase but I’ve said on
occasion “it’s only jewelry; if you don’t love it,don’t buy it”.

I’m a bit sensitive on the topic of opal after listening to
commentary by art fair goers for the past number of years.

I only sell at retail, at art fairs where I hear the most outrageous
comments concerning opal, i.e. : “our mother told us we couldn’t wear
opal because we’re Irish” said with an absolutely straight face. I
should have been writing this stuff down.

I personally make and have sold lots of opal jewelry. It’s my
favorite stone to cut. There is so much uninformed comment about
opal material ( present company excepted ) that I feel I have to
respond. Nothing personal as they say.


#16

Hi Beth -

I *have* seen it spontaneously craze. The Coober-Pedy material I
often use is especially prone to this though I've seen it (more
rarely) with boulder opal. 

Trust your dealer. If they don’t stand behind their material, I’d
look elsewhere. And, opal is expensive. There’s a lot of junk being
sold.


#17

Hi Sophie,

that the opal will become hot. this is not good for opals with even
slight flaws. keep it cool with water. and please be aware that
this is in no way, as far as I know, a conventional way to polish
opal. But I have recently been enjoying working with opal without
any conventional lapidary equipment and these are the final steps
that I use to get a high shine, glassy finish. 

Thanks for the advice. I’ll give it a go and see what happens. As it
is at the moment, it’s not usable at all so there’s nothing to lose
by trying to save it.

Lovely opals BTW. I particularly like the boulder opal.

Thanks again.
Helen
UK
http://www.hillsgems.co.uk


#18

I love opal. It was my first stone to cut and still the one I go
back to to get refreshed.

It seems that opals from many locations are quite stable whereas
others can be notoriously unstable. I’ve never had a problem with
spontaneous cracking in Australian opal. Although I’ve heard that
the stone from a small remote field called Lambina, which can produce
extraordinary stones, can be a problem. (for a photo of an amazing
lambina opal go to my web page gemmaker.com and look at the carved
flower I use for logo.)

I have talked to other cutters and jewelry makers who have
experienced problems with unstable opals as well. I believe the
tendency towards crazing is directly connected with the degree of
translucency of the stone. What’s known as crystal opal, the very
clear material, can have a greater problem with stability than would
white opal, for instance.

Like Hans, I’ve had some problems with Mexican opal. I cut a
beautiful highly translucent red cab that when I looked at it 6
months later had cracked. Even some of the while Mexican has cracked
on me. Ethiopian opal is well known for instability to as much as
50% of loss and even the Ethiopian dealers I’ve spoken with will
readily admit this.

I’ve had Honduran opal rough that I bought when it was in water. The
stone was all clear when I bought it and about half of it went
cloudy once it was out of water for a month or so.

Chemically opal, of course, is SIO2 H20. Some people say that the
crazing, if it’s going to be unstable, comes from the evaporation of
water from the stone. I don’t know if this is true, but I’ve
certainly seen opal crack. I do know absolutely that it does not
take well to heat. It’s especially fun and terribly easy to crack
them with overheating. Opal also does not like to be frozen and
might well crack if it is. Again water content would make sense.

By the way, for Helen who enquired about polishing the old stone,
actually older stones, mined roughly more than around 50 years
previous, whether opal or even other species can be particularly
susceptible to crazing when repolished. All the scratching on the
surface should tell us that it’s had some rough treatment and been
seriously abraded. So that might affect the internal structure and
there may be cracks in there that you can’t see.

I’m told that older stones can also be more susceptible to changes
in internal stresses when changes are made on the surface. Don’t
know the truth of that, but I do know that there’s a greater chance
of instability in older stones. Let’s face it stones can change a
lot due to outside changes in environment. Many stones can fade in
long exposure to sunlight, I believe people talked here about
kunzite color-fading. Some topazes can fade as well, especially the
redder colors. Amethyst can fade, too etc.

I’ve experienced the problem of recutting very old stones myself and
spoken with other people who’ve also had the problem and those
weren’t even opal. But older opal can be worse. Furthermore the
approach you were asking about for polish, using a metal polish,
would be particularly dangerous for the stone because you’d be far
more likely to generate heat that way. If you want to take the risk
of polishing it, it really should be done wet with cerium or
aluminum oxide on damp leather. But it would also need to be
prepolished first.

And yes, Fred Ward has gone through a terrible time with that
lawsuit. So that’s a cautionary tale. I guess in the final analysis
the conclusion has to be that stones do lots of different things
that change them. It’s why we love them isn’t it?

Finally, just for general please folks be aware that at
the moment, because of fuel prices and other factors, mining for
Australian opal has significantly shrunk so sooner or later the
supply will be very much affected. This is also true for many other
products of mining, especially in the gem stone categories. Mining
after all is a very energy intensive activity. Metal supplies on the
other hand might increase since old mines are being reopened as the
cost of metal has escalated so much. But in stones, and certainly in
Australian opal, some things may get ever more scarce. I mentioned
the Lambina opal field earlier. I understand that it is such a
remote and forbidding location that they have to bring absolutely
everything in to operate there, all food, water, fuel, etc. So that
field has at least for the time being been all but abandoned.

This having all been said, I hope people incorporate opal into their
jewelry all the time. I can’t get enough of the stuff.

Derek Levin
www.gemmaker.com


#19

This entire thread is pretty much about “conventional wisdom”.
Conventional wisdom says don’t use opal in rings. It also says don’t
use it at all, because it’s not especially stable. And there are
reasons for that, all related to the hydrated crystal, pretty much.
I’d have to side with Kevin here, and no, it makes no sense when
it’s logically analyzed. If you go by the conventional wisdom, you’d
never sell an opal. People want opal rings (I’ve made many) - what
are you going to do, kick them out? It’s a fragile stone, it has
issues, people still love it and want it - it’s just part of the
story. Talking to customers and education about the properties of all
stones is all one can do. Opals would never be sold, if logic ruled.
As one today I neglected to copy/paste said, “All opals craze, you
just haven’t waited long enough.” Whether that’s literally true or
not - I sold a black that was 150 years old a few years back -
there’s no doubt that opal has issues. That doesn’t mean people don’t
want to buy and wear it, though. It’s one thing to guide people, it’s
another to try to imprint them…

http://www.donivanandmaggiora.com


#20

Opal can indeed surprise the unwary: a few years back I gave my wife
a fairly large Australian Coober Pedy opal that I had set as a
pendant in gold. It was perfectly sound, apart from some slight
inclusions of sand. I found recently when I looked at after 35 years
in her jewelry box that it had developed numerous cracks throughout.
Other opals from Coober Pedy, Andamooka, and Lightning Ridge that had
been in the same box for just as long were not affected at all! Of
the many Australian and Mexican opals that I have cut and polished,
very few have self-destructed like that. This instance would appear
to warrant the statement that it had cracked "spontaneously. " Ok,
I’m not the most experienced person on this list, but why hasn’t
anyone brought up the fact that you should not let opals get hot or
dry out? Many opals have water inclusions, really minuscule “bubbles”
(which are often in really thin planes, lending extra refraction) all
the way thru the stone. (We’re talking about precious opal here) I
have several pieces of opal jewelry, as does my Mom, (both my mother
and partner have opal as their birthstone) and we make sure to get
ours wet at least once a year or so. We’ve never had an opal crack.
Just my two cents.

Lindsay Legler

Oh, and here’s from Wikipedia:

Opal is a mineraloid gel which is deposited at relatively low
temperature and may occur in the fissures of almost any kind of
rock, being most commonly found with limonite, sandstone,
rhyolite, and basalt. The water content is usually between three
and ten percent, but can be as high as 20%. Opal ranges from
clear through white, gray, red, orange, yellow, green, shore,
blue, magenta, rose, pink, slate, olive, brown, and black. Of
these hues, the reds against black are the mostrare and dear,
whereas white and greens are the most common; these area function
of growth size into the red and infrared wavelengths. see
precious opal. Common opal is truly amorphous, but precious opal
does have a structural element.