Heating princess diamonds?

Jewelry Discussion
41 
Leonid, are you writing about the diamonds I come across, 1/10ct
or smaller, illusion set, full of black inclusions and bought off a
shopping channel? These will shatter if you sneeze at them!

They probably would. I have received my diamond credentials from GIA
in 1980. At that time, nothing less than SI2 was used for jewellery,
and even that was rare. VS2 - SI1 was the low range. As far as I am
concern, it is still is. Personally, I have never handled anything
below VS2 and I never will.

What needs to be understood is that diamonds, if quality is not a
consideration, are not rare. In order for a specimen to be called a
gemstone it must be durable, beautiful, and rare. When I talk about
diamonds, I talk about What you describing are obviously
not.

Leonid Surpin

42 
CZ will not crack if heated, but quite often it looses
transparency. Kind of a bluish haze. Degree of damage varies, but
if one look really close, it is there.

Not always true, the only white stone I ever really damaged with a
torch was a 1 ct cz. Rush job but all standard precautions followed.
Since then they come out or are broken out with a promise to replace
with a new un scratched stone (client informed and consenting). I
have done many bad things to stones over the years (and been very
lucky) but that one cheap stone still haunts me. 99% of the time I
can get away with murder, it’s that 1% confessing which really hurts.

jeffD
Demand Designs
Analog/Digital Modelling & Goldsmithing
http://www.gmavt.net/~jdemand

43 
However, a design that cannot be completed unless soldering ~on~
the diamond takes place is one that should be revisited.

Somebody the other day asked about the hows and wherefores of
soldering diamonds. Hans’ comment above shows a common attitude,
here on Orchid - that there’s something scary, strange or dangerous
about doing it. In reality it’s an everyday occurrence - since
diamonds can take the heat of normal gold soldering, it’s a property
that is used to it’s best advantage in the diamond jewelry industry.
Yes, the pieces I showed ~could~ be done with out soldering. Most in
twice the time at half the quality. Since the stones can be soldered
on, you set the channel, polish everything up and just set it in
place - quick, clean and easy. Just like the “Casting VERSUS
Fabrication” thread - sure, you can fabricate it, but why would you?

I get the feeling that many folks are getting set up, lighting their
torches, tensing up their backs and tentatively going in. Then
saying, “Whew, made it!” when it works. If you use a boric
acid/alcohol dip, use normal soldering procedures and don’t get them
glowing orange there’s no reason you can’t solder on diamonds just
like you solder on gold. I’ve done it up to around 10 carats or
so…

There are caveats: They must be surgically clean. Neil wrote about a
burned pavilion today - I wonder if the stone was clean on top, but
not the bottom. If there is dirt or grease, it will burn and burn
into the stone. I (and Peter’s explanation) already mentioned that
stones can break from the contraction of metal, but if you have
channel setting and the stones are touching or overlapping, they can
chip each other in the same way. That’s pretty common, in fact, and
it’s something to really look out for.

I burned the point off a marquis as a youngster. I’ll lay out
baguettes on masking tape to do the work. Was a time I soldered on
some and they came out burned. I realized it was because I hadn’t
washed off the glue residue from the tape… Other than that I
have NEVER burned a diamond, and I’m not exaggerating when I say how
many I’ve soldered on. Chipping and such from the things in the
above paragraph - occasionally, yes.

It’s like (what should be a mantra in) polishing - “if there are
scratches it’s because you put them there.” If the diamond is too
hot, it’s because you made it so…

It’s just not a big deal…

44

As I remember my training, and as I practice…

  1. Have everything ready.

  2. Inspect the jewelry. If there is a good reason you shouldn’t heat
    the stone, then don’t.

  3. Clean the jewelry. Someone mentioned frosting of the stone near
    the girdle. Under prongs is a good place for dirt/grease to remain
    hidden.

  4. Dip the diamonds in firecoat (borax & alcohol). This reduces
    oxygen access to the stone, but it won’t last forever, so don’t
    delay.

  5. Go in, solder, get out. The effectiveness of the firecoat is
    reduced as it absorbs more oxygen.

  6. The game changes for platinum since there isn’t a firecoat
    effective at the temps needed to weld platinum.

Having said the above, I will agree that there will arise situations
that call for different procedures. Ok, then keep some basics in
mind. Protect the stone, protect the jewelry, get in/out quickly
while soldering efficiently and modify the procedures to accomplish
this.

Mike DeBurgh, GJG
Alliance, OH

45

Hi there, I read what I had sent and need to make a small
correction- I had said a #3 tip but I had used the #4 tip. It’s
changed below.

46 
Zirconium Oxide exist in natural form. It is gemstone called
zircon. CZ is a cubic form of Zirconium oxide

Zircons are Zirconium silicate - ZrSiO4
Cubic zirconia are Zirconium oxide ZrO2

Tony Konrath

47 
Result: one soldered platinum ring, diamond intact, no loss of
clarity..etc

Why did you opt for torching rather than lasering?

48 
For the amount of time, and I felt like I was working in slow
motion, it would have been cheaper to buy a new one. But I felt
like it was a moment of challenge

At my first place of employ they had the notorious $95 telephone
hook. The silversmith had constructed quite an admirable device to
clasp the phone hand set while on hold (this goes back a
ways…70’s). It was precisely made with all details tended to. Truly
a masterpiece in sterling. Took him most of a day to make.

There was however, a very convenient shelf just below the wall phone
that worked equally well.

49 
3. Dip the diamonds in firecoat (borax & alcohol). This reduces
oxygen access to the stone, but it won't last forever, so don't
delay.

I assume you meant Boric Acid not Borax. Borax is not soluble in
alcohol, Boric Acid is.

James Binnion
James Binnion Metal Arts

50 
Why did you opt for torching rather than layering?

There are reports of diamonds been damaged by use of lasers for
repairs. Laser beam has enough energy to damage a diamond, so it is a
real possibility.

Leonid Surpin

51

Zircons are Zirconium silicate - ZrSiO4
Cubic zirconia are Zirconium oxide ZrO2

This is probably will put everybody to sleep. Zircon is classified as
orthosilicate. Orthosilicates responsible for large number of
Garnet group is among them. Orthosilicates can be
schematically represented as [one or more metal] + [tetrahedra];
tetrahedra been SiO4. For example: garnet almandite - Fe3Al2(SiO4)3,
Penakite - Be2SiO4, and others. As a member of orthosilicates it is
correct to write zircon as ZrSiO4.

However, such view are not helpful in understanding of why such
mineral as Baddeleyite (ZrO2) is rare, and why zircon is a metamict.
To avoid confusion with CZ - CZ is cubic, while Baddeleyite is
monoclinic. If we write ZrO2 + SiO2, what we are saying is that zircon
is Baddeleyite with admixture of silicon dioxide. Some may point out
that zircon is tetragonal, while Baddeleyite is monoclinic. This can
be explained by noting inherent instability of zircon oxide lattice
and therefore having tendency to include other elements to stabilize
itself. Existence of varieties like oyamalite, which contains up to
18% of yttrium oxide, seems to confirm that theory. This also
explains phenomena of metamictization.

It is interesting to note that another metamict Titanite (gemstone
Sphene) CaTiSiO5, makes more sense if considered as CaO + TiO2 + SiO2.
Lab-grown titanite used as diamond substitute as well. Anyway, most
of the mineralogical books list zirconium as you correctly pointed
out, as ZrSiO4.

Leonid Surpin

52

Thanks for the correction Jim. Yes indeed, I meant boric acid, not
borax. Oftimes there’s many a slip twixt the brain, finger, and send
button.

Mike DeBurgh, GJG
Alliance, OH

53 
Why did you opt for torching rather than lasering?

I don’t like using the laser for anything structural - with it being
a knife-edge shank, the joint was a very narrow strip, and I’ve
never been happy with the strength of lasered joints. On the other
hand, I did laser the back of the shank, where I re-sized the ring,
because this was relatively thick (about 2 x 2.5mm), and not a focal
point for stress.

The other concern is that I find a higher laser focus preferrable
for platinum, which increases the likehood of the pulse reflecting
unpredictably - the joint went from the base of the collet up to the
bezel, so I was worried about a reflection OR a mistake on my part.

I certainly would have preferred not to use a torch on this job, but
there seemed to be no other choice. Does anyone think I made a bad
choice here - if done well, can a narrow lasered joint be strong
enough?

Jamie
http://primitive.ganoksin.com

54 
Does anyone think I made a bad choice here

Situations like these come down to judgement call. Only you (or
whoever) can make that call because you can see what you’re dealing
with, not only the piece but also the business situation. The ring
was sold, you had to deliver. Therefor you chose the method you felt
most assured the right outcome.

Yeah lasers aren’t all that hot for narrow cross sections where
there’s no room for fill. Without fill its a spot weld of limited
penetration. Very unlike an electric spot weld that goes thru both
pieces in a join(primarily sheet metal lap joints) a laser weld is a
surface weld. Crank it up for a deeper weld and you might wind up
with hellatious porosity. And once its there, it is there, you can
cover it but the porosity and weakness is underneath, just waiting
for the technician to think he’s done a good job before cutting him
down to size!

What did you use for solder? Personally I’d scratch my head awhile
over that decision. On the one hand 20KWW is plenty strong and I’d
rhod over it anyway but its not plat. Then again I’ve seen a fair
amount of handmade plat rings assembled with WG solder, from the
factory. I think that’s stretching the bounds a bit to still call it
platinum. But plat solder carries risk that close to the stone in
your situation. You could pull the stone and use hard or medium plat
solder but can you be sure the tips will still look right? Its a
balancing act sometimes, sounds like you didn’t drop the ball. Any of
'em.