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Garnet, gold and heat


#1

Friends-- I have a pair of very attractive stud earrings, gold
(14k?) and orange garnet (at the moment, the name escapes me). The
back has broken off one, leaving just a bezeled stone. (The back was
basically a “T”, with the top soldered to the bezel on its ends.) I
cannot open the bezel without destroying it. So, here’s the
question-- can I solder a new back on this without ruining the
stone? I don’t think water will work-- there’s very little clearance
under the stone. I could fit in a little heat shield, and use the
Little Torch to solder. The stone is quite clean, internally.

Any suggestions? Thanks!

Noel


#2

Noel,

Any suggestions? Thanks!

Sure, send them to me! (Just kidding – I picked up a pair of
spassartine garnets last February at the Tucson show and set them
with Turk’s Head bezels in a pair of stud earrings, so your plight
got my attention.) I know next to nothing about those gems, or any
others, with respect to heat treatment, so the following is
definitely not an expert opinion.

It’s my impression from what I’ve read that the orange garnets are
not heat treated, so if you heat yours, I have no idea what color
they might turn. Is there any way you can un-set the stones so you
can repair the bezel without risking heat on them? Mine are so
pretty that I’d regard it as worthwhile to go to that much extra
labor, if it’s possible.

Good luck,

Loren
http://www.golden-knots.com/


#3

Noel, Garnet is very heat sensitive. It will sometimes pop with the
temp of dop wax, around 140 F. You will need to unset the stone to
repair the earring.

Don


#4
    Noel, Garnet is very heat sensitive.  It will sometimes pop
with the temp of dop wax, around 140 F.  You will need to unset the
stone to repair the earring. Don 

I’m sorry Don, but my experience refutes your statement. I have
re-tipped on garnets, soldered bezels with garnets set in them.
Granted, the work was done with 14K easy solder in most cases, but I
find them to be relatively tough. I’m sure there are exceptions, but
they won’t be typical.

David L. Huffman


#5
    Friends--    I have a pair of very attractive stud earrings,
gold (14k?) and orange garnet (at the moment, the name escapes me).
. . . . question-- can I solder a new back on this without ruining
the stone Noel 

Hello Noel; I’ve found that mozambique, almandine and rhodolite
garnets will all withstand the heat of soldering. It’s possible that
what you are describing is a mandarin garnet. I don’t know if those
will take the heat of soldering, but it’s possible. We’ll need one
of the stone specialist’s opinion. Garnet will withstand soldering
heats, but precautions should be taken. Make sure they’re clean, the
piece is coated with boric acid and alcohol, and bring the heat up
slowly before you get down to the business of melting the solder.
All this is academic, really. If you do have a mandarin garnet,
those are getting hard to come by and will likely become pricey if
they aren’t already. Why not see if there is one of our Orchid
friends who had a laser who can weld it on for you? That way, you
won’t have anything to worry about. I’m assuming the stone is set in
a bezel, as you are describing it. If it were simply a prong
setting, it would be a simple matter to remove the stone, repair the
earring, and re-set. Call me a coward, but any more, with possibly
expensive stones, I tend to err on the side of caution. If you found
out that were and expensive stone AFTER you’d tried soldering it and
destroyed it, you’d wish you’d decided to carefully saw the stone out
and remake the entire earring. I’d look into the laser solution.

David L. Huffman


#6

Don’t heat it. You will break it. Remove it and make a new bezel
for the stone. Charge accordingly.

Daniel R. Spirer, GG
www.spirersomes.com


#7

Noel, the easiest repair solution is to have the back laser welded
back in place, there would be no risk to the stone with this
technique. If you don’t know of anybody in your area with a laser
welder get ahold of me offline and I’ll direct you to two good people
who do have them, you can choose which you’ll use yourself; I use
both of them regularly. Paul Reilly; Colorado Springs, Colorado


#8

Laser Welder, there are many people who would do the job or probably
show you how. If you do not know who they might be, call up Laser
Star in Cranston, RI and ask them who has the lasers in your area.
Sara


#9

This is a job for a fusion finding unit like the Sparkie made by
Triad, or laser welding.

Rick Hamilton


#10
  Garnet is very heat sensitive.  It will sometimes pop with the
temp of dop wax, around 140 F.  You will need to unset the stone to
repair the earring 

Don’t know if I totally agree with the above. Some garnets may be
heat sensitive, but my experiences with pyropes is just the opposite.

I made several bracelets using 4 mm pyrope beads centered in a 4.5
mm 14 ga 1/2 rnd sterling ring. The beads were strung on 20 ga
sterling wire which was soldered to the 14 1/2 rnd. I’d say that I
had less than 2 out of 100 beads break using medium solder.

Dave


#11
  Why not see if there is one of our Orchid friends who had a laser
who can weld it on for you? 

I concur with Mr. Huffman! I think this is a case when you should
send it out. A quick and easy job for a tradesman with a laser
welder, with no risk whatsoever to the stone. Too many unknowns about
the stone, and a lot less time/effort than removing the stone for the
repair, or remaking the setting as you indicated you’d have to do.

If you don’t get any Orchid members popping up offering to do it, I
believe I can refer you to someone, who I haven’t used before. Email
me offline if you’d like me to track the down.

All the best,
Dave
Dave Sebaste
Sebaste Studio and
Carolina Artisans’ Gallery
Charlotte, NC (USA)
dave@sebaste.com


#12

noel, can you find someone with a laser welder? that way you could
avoid heating the stone and not have to remove the garnet i’ve used
it one some pretty sensitive stones opals etc.


#13
 I'm sorry Don, but my experience refutes your statement.  I have
re-tipped on garnets, soldered bezels with garnets set in them.
Granted, the work was done with 14K easy solder in most cases, but
I find them to be relatively tough. 

David, I am quoting from the GIA Gem Reference Guide on cleaning
methods for Garnets

Almandite Garnet                	Steamer: Never
Andradite Garnet                	Steamer: Never
Grossularite Garnet             	Steamer: Never
Hydrogrossular Garnet   		Steamer: Risky
Malaia and CC Garnet    		Steamer: Never
Pyrope Garnet           			Steamer: Risky
Rhodolite Garnet                	Steamer: Never
Spessartite Garnet              	Steamer: Never
GGG                             		Steamer: Usually Safe
YAG                             		Steamer: Safe

If the stones will not stand the heat of a steamer, around 230F or
so, how do you expect them to stand the 1150F or so required for
soldering?

Your experience doesn’t seem to follow the general experience of the
gem trade or the jewelry trade. There have been products developed
to accommodate the heat sensitive nature of garnets when dopping
them. All of the documentation I have on Garnets list them as “Heat
Sensitive”. To attempt to solder with any solder, especially a Kt
gold solder on a garnet is unwise.

I once soldered a bezel containing a Moonstone on a ring I was
repairing. I anticipated replacing the stone after the solder work
was done. It was going to be easier to replace the stone after the
repair was complete. I was shocked to find that the stone wasn’t
damaged. Would I attempt to try it again, expecting the stone to
remain intact? Not a chance. It was a fluke, pure and simple.
Perhaps your experience with garnets are similar to mine with the
moonstone.

The “re-tipping” of stones should be limited to the Red, White, and
Blue, and the Red doesn’t include Garnets. Even with care, the Red
and Blue can be damaged during a re-tip soldering operation. The use
of the Boric Acid dip can cause surface problems on Rubys and
Sapphires. Lack of it can cause burning of Diamonds. Garnets just
don’t fit into this treatment.

Don Rogers
Campbell Gemstones


#14

Hello Don and David, Have to add my US$.02. I have sized silver
rings with garnets in them, fully anticipating that the stones would
be damaged and I would replace them. With bezel settings, that
would be less work than trying to remove the stone. Anyway, the
garnets survived, much to my delight! These were inexpensive
stones, and if they were more costly, I’d not have tried it. I
think, that’s the factor - whether or not the stone can be easily
replaced. If it’s irreplaceable or expensive, don’t risk heating
it. Judy in Kansas, where we NEED RAIN badly!!

Judy M. Willingham, R.S.
Biological and Agricultural Engineering
237 Seaton Hall
Kansas State University
Manhattan KS 66506
(785) 532-2936


#15

Don, Sorry to be a spoil sport but I regularly solder and heat
colored stones.I make sure they are clean and coated in boric acid I
have been doing it for years.I don;t recommend it for everyone but it
works.Yesterday I soldered a head on a seven stone mothers ring,Did
not crack or break one stone and it was no fluke.I don’t direct the
heat on the stone directly and put the ring on a steel ring mandrel
after the torch is turned off.Cz’s and other stones are cast in place
yet if you go by the sheets they are not supposed to take
heat.Regards J Morley


#16
    Your experience doesn't seem to follow the general experience
of the gem trade or the jewelry trade 

Hi Don; I don’t want to seem contentious, but I’m not pulling this
out of thin air. It comes directly from my own
experience. Whether people choose to believe me or not is their
choice, but cheap garnets can be had to experiment on. I’m going to
stick with my story and I believe some others will concur with me.
After I wrote that post, I went to my shop, picked up a 5 mm
Mozambique garnet, put it on my soldering pad and slowly heated it to
a visible red. I let it cool, examined it with a 30 power loupe, and
there was no change. Perhaps I wouldn’t have been able to do this
with a larger stone, but I’m going to try it some day just for the
experience. I respect GIA’s opinion, but I believe there’s a point
at which they err on the side of caution. I certainly have no fear
of steam cleaning a garnet. From time to time I get to pay for my
scepticism, but hey, that’ how I learn sometimes.

    I once soldered a bezel containing a Moonstone on a ring I was
repairing. I anticipated replacing the stone after the solder work
was done. It was going to be easier to replace the stone after the
repair was complete.  I was shocked to find that the stone wasn't
damaged. 

I once, early in my career, sized a silver ring with a moonstone in
it, and as much care as I took to protect the stone, it still cracked
down the middle. Since then, I don’t let them get too warm. Your
advice on “Red, White, and Blue” is sound, and of course, there are
conditions where that rule of thumb needs to go further (Hmong Su
ruby, unheated sapphires with possible gas containing negative
crystals, drilled and filled diamonds, etc.). My rule of thumb is
"when in doubt, play it safe, unless replacement is cheap and easy
and you feel like possibly wasting some time". I think we would both
agree that in the case in question, at the very least, if the stone
is damaged, it will mean considerable work fixing it and possible
difficulties matching the other stone. Consensus seems to be that
it’s advisable to use a laser to weld the post on. Hope I haven’t
given the impression that I don’t hold your opinions in high regard.
Perhaps, as you say, I’m pointing to an anomaly.

David L. Huffman


#17

I have never soldered directly on a garnet. I have however steamed
them for years with not a problem, ever. I usually only work with
rhodolite or pyrope. I just took a 6x4 oval rhodolite cab, alcohol
and boric acid protected, heated it till just glowing from the heat,
as it heated it fractured across the center the 4mm direction. I
would not trust doing that unless I wouldn’t care if I had to replace
the stone as a strong possibility during a repair, if I thought I
might have to pull the stone and damage the metal and the cost to
repair metal was more than the cost of replacing the stone.

Richard in Dry, Hot Denver


#18
      Your experience doesn't seem to follow the general
experience of the gem trade or the jewelry trade 
       Hi Don; I don't want to seem contentious, but I'm not
pulling this out of thin air. 

To add another voice of experience (30+ years) to this debate, I’ll
side with David here. Remember that garnets form in contact
metamorphic zones, much the same as do sapphires and other such.
Temperature itself is not usually a problem. As with many other
stones, it’s not the temperature itself, but the sudden changes
thereof. If you take your time so the stone is raised in temperature
gently, it will much more likely withstand the process. I’ve more
than once seen garnets, usually common dark red varieties, with a
bit of torch damage consisting of melted facet edges, but no actual
fracturing from the soldering heat. And i’d remind some that one
used to be able, and may still, be able to buy a soldering board, as
well as a variety of soldering sand that is simply garnet sand. It
holds up very well through repeated use.

When GIA puts out those charts, remember that they must err on the
side of extreme caution. If they listen to the above experience,
which they’re well aware of, and say garnets can take some heat, sure
as shooting some idiot will take a torch to a 20 carat gem quality
tsavorite and split the sucker into pieces. And since the dangers of
heat shock increase with the size of a stone, Almost ANY large stone
has to be treated with care, even with just the steam cleaner. Keep
in mind that those charts are used by a lot of otherwise totally
untrained and uninformed and gemologically naive sales clerks, many
of whom know which stone is which only be reading the price tag. I’m
certainly not saying sales clerks are all idiots, most aren’t in
fact. But there are enough of those part timers in the mall stores
that do fit this, and for whome the only source of may
the chart from GIA that the manager stapled up by the cleaner, that
GIA really has to report the worst case situations on the gems, not
the most likely situation.

Garnets are not immune to heat damage. But many varieties seem to
be fairly stable in color with heating, and if the heating is gentle
and at least a little gradual, and the stone is not badly included,
then more often than you’d expect, they’ll survive considerable heat.
At one point way back in school, I played with casting stones in
place in silver setting. About 2/3ds of the attempts with garnets
worked without damage to the stones.

And most goldsmiths you might ask, I think will be able to give you
similarly mixed memories, suggesting that garnets, while not immune,
are also not instant casualties when heated. So the “general
experience of the gem trade or jewelry trade” kind of would depend on
just whom you ask, and how you phrase the question. If you ask, are
garnets ever damaged by heat, the answer is of course, yes. If you
ask, do garnets sometimes survive being directly soldered on, those
who’ve tried it will also say yes. Just be gentle, don’t point the
torch directly at the garnet, but rather tangent to it, just
brushing the metal, not the stone itself. And for heavens sake, let
it gently air cool. don’t quench. And do this only with stones you
can afford to replace if it doesn’t work.

Peter Rowe


#19
Sorry to be a spoil sport but I regularly solder and heat colored
stones.I make sure they are clean and coated in boric acid I have
been doing it for years.I don;t recommend it for everyone but it
works.Yesterday I soldered a head on a seven stone mothers
ring,Did not crack or break one stone and it was no fluke.I don't
direct the heat on the stone directly and put the ring on a steel
ring mandrel after the torch is turned off.Cz's and other stones
are cast in place yet if you go by the sheets they are not supposed
to take heat 

I have had a lot of contradiction to my earlier statements on the
heat sensitivity of Garnets. I was quoting trade references and
past experience as a Faceter, and as a goldsmith. I am always
willing to consider other opinions on the subject. You never learn
if you are closed to ideas that are not your own. I share my
experiences with this list, assuming that others might have a
different view, and with the knowledge that I may be wrong on
occasion. However, whatever knowledge I have gained from " the
school of hard knocks", I tend to value the most. It may be wrong,
but it is a safe harbor when in doubt.

The great thing about this list is that different experiences are
presented. The choice of which experience the readers wish to
follow is theirs. They are given options that they may not have
considered before. This is not a contest about who gets the most
points, IE who is “right the most times”. It is an exchange of
ideas. If you are “keeping score”, go somewhere else. There is a
lot to learn here. Even for the old timers.

Nuff said on my part.

By the way, this response was not directed at the person who I
quoted at the start. That person stated “I don;t recommend it for
everyone but it works”. That is a valid statement. Just as my
statement the I have had garnets crack with the temperature of the
dop wax is valid. Both are more for you to sort out
when making the decision what to do at your bench. Neither are the
absolute last answer.

Don


#20

One of the great things about this list is the exchange of ideas. I
don’t agree with some of the opinions and observations, and it is
quite clear that some don’t agree with my opinions and observations.
This is a good thing as it presents different ideas to the readers
of the list. I have picked up many good “tricks”, ideas, and pieces
of knowledge from those who contribute to the list.

I do tend to err on the side of caution when in unfamiliar
territory. I have been burnt re-tipping some stones, including a
small but very nice sapphire of all things. I have gotten away with
doing things that I shouldn’t have, sometimes by design and
sometimes by stupidity on my part. When cutting opals, I routinely
dop the opal using a brown faceting wax. I have no problem fanning
an opal through the flame of an alcohol lamp until the wax flows. A
lot of cutters cringe at the thought. Others say Yep, so what. I
put opals in the ultrasonic (for a brief time and in the area that I
know is somewhat quite) and then Steam them dry (but not in the hot
part of the steam jet).

The point is that if you know you can do something, do it. If you
are not sure, but can afford to fail, try it. If you can’t afford
to fail, or you are sure you can’t do it, don’t. Isn’t life simple.

Don