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Gold plating a ring with set lapis?


#1

Hi all - I was wondering if it is an issue plating a silver ring
that already has a lapis in it. As I understand it, the ring needs to
be polished and completely finished when plated and that includes all
stones set. I’m going for a vermeil-thickness plating but am a
little worried about the plating process affecting the stone
(changing the color, polish perhaps, etc.). Has anyone ever gold
plated a ring with a set lapis? Any thoughts?

thanks!
cheyenne


#2

Hi cheyenne;

Though I have not gold plated a Lapis set item, I have cleaned one in
an ultra sonic cleaner and to my shock ruined the finish on the
stone. I suspect you might run into the same problem. Also doesnt
Lapis metallic inclusions and would they also try to plate too


#3

Cheyenne- Don’t do it.

When I was a newbie, I had to replace an expensive piece of lapis
just by putting it in the sonic. I’m afraid that you’d be unable to
get it sterile enough with out harming the lapis. Let alone the heat
of the electro cleaning and plating solutions.

My rule of thumb is that I never do anything I’m unsure of with a
stone I can’t afford to replace.

Have fun and make lots of jewelry.

Jo Haemer
www.timothywgreen.com


#4

Dear Cheyenne,

Yes, there are issues with gold plating a ring with set lapis. You
will need to coat the stone CAREFULLY so that the plating won’t leach
out the lapis. I have used a few light coats of clear nail polish
(Sally Hansen- Hard as Nails) before sending it in for plating. Just
be careful that you don’t hit the bezel with the nail polish or the
plating will skip. Make sure the nail polish is thoroughly dry before
sending it out. Hang it upside down for a bit while drying.

Platers usually have a masking agent- if you are really worried, ask
the plater to mask the stone for you for a small fee. When you get
the ring back, you can clean off the nail polish with either acetone
on a Qtip or Orange Glo or Goo Gone on a Qtip.

Good luck.
Ruthie Cohen


#5

Hey

Lapis is a porous material, may have been died. I wouldn’t do it, it
may get dull or loose it’s color.

Hans Allwicher
http://www.hansallwicher.com


#6

Don’t do it. You will etch your stone and for that matter you will
etch any stone that is soft or is not a crystal. AND EVEN SOME OF
THESE WILL CHANGE COLOUR. Any and all acids have a specific use and
you need to kno w your chemicals, theIr effects, and uses,
particularly mixing them together, PLEASE DON’T HURT YOURSELF OR
BURN YOUR LUNGS. 210.260.0662, I’LL HELP YOU ANY DAY OF THE WEEK IF
ASKED

Stephen Wyrick, CMBJ
Gemmologist


#7

Never plated an article with lapis in situ but see little to worry
about other than calcite content. S American lapis can have a high
proportion of calcite, Afghan tends to be lower apart from in the
very bottom grades. The acid in the plating solution will attack this
quite readily. You could always coat the stone with a resist such as
lacomit and then clean it off with acetone afterwards.

Nick Royall


#8

Overseas cutters generally wax lapis to bring it to a decent polish
(lapis is a mixture of several different chemically related
minerals) quickly. Exposing to some of the liquids used in our
ultrasonics can quickly damage that wax finish (although a good
furniture wax will save you!). Using a resist is not generally the
best answer, as whatever you use to remove the resisit will remove
the wax finish as well, if it is indeed present. Another thing to be
concerned about is the presence of pyrite in the piece, either
microscopically or clearly visible. That plates, too!

I have often brought really good, dense lapis to a mirror polish
using diamond on a resin lap, or chromium oxide on a dampened leather
lap, but. …some is more coarsely grained and/or chalky and will
never take a fine polish. So, not ALL highly polished lapis is waxed
or dyed.

Wayne Emery
www.thelittlecameras.com


#9
Also doesnt Lapis metallic inclusions and would they also try to
plate too 

The inclusions in Lapis, when they are there (they aren’t always
present) are not metallic. They are iron pyrite, also known as fools
gold. That’s a sulphide. But it doesn’t matter. Even if they were
metallic, they wouldn’t plate, since they’d not be electrically
connected to the circuit. And even if they were somehow connected,
despite being imbedded in the insulating lapis, it still wouldn’t
matter, since they are already gold color. More gold plating on the
pyrite wouldn’t look different, or not by much. Of more concern,
though, is simply that lapis is often a bit porous, so it can absorb
some of the plating solution. Likely, cyanide, so not a good residue.
And if any acid bath step is used (often some sort of acid is used as
a surface activator in some plating sequences), then both the pyrite
inclusions, and the almost always present calcite componant of lapis,
are vulnerable to it. I’m not sure if the hot cyanide plating bath
itself (pretty caustic stuff) would affect the lapis, but wouldn’t
want to bet against it.

Peter Rowe


#10

Problems to consider…

  1. precleaning. hot tank solutions will likely etch the lapis. any
    mask you may apply stands a good chance of being removed in the
    process. acid dip won’t be painless either maybe. you could steam but
    effective cleaning might be iffy. If you remove mask w acetone, be
    certain the stone wasn’t dyed.

  2. an acid based plating solution will etch the lapis. if you use
    cyanide based, can you be absolutely positive you can rinse it all
    away, even under the seat? And as Hans says, lapis itself is porous.

  3. IF you manage to sidestep the problems and get a good plate,
    what’s a plated ring going to look like after a few weeks of wear?
    You might be replating every few months to keep your customer, ready
    for that?


#11
The inclusions in Lapis, when they are there (they aren't always
present) are not metallic. They are iron pyrite, also known as fools
gold. That's a sulphide. But it doesn't matter. Even if they were
metallic, they wouldn't plate, since they'd not be electrically
connected to the circuit. And even if they were somehow connected,
despite being imbedded in the insulating lapis, it still wouldn't
matter, since they are already gold color. More gold plating on the
pyrite wouldn't look different, or not by much. Of more concern,
though, is simply that lapis is often a bit porous, so it can
absorb some of the plating solution. Likely, cyanide, so not a good
residue. And if any acid bath step is used (often some sort of acid
is used as a surface activator in some plating sequences), then both
the pyrite inclusions, and the almost always present calcite
componant of lapis, are vulnerable to it. I'm not sure if the hot
cyanide plating bath itself (pretty caustic stuff) would affect
the lapis, but wouldn't want to bet against it. 

With all due respect you possibly could be correct but you need to
be aware that plating solutions contain an abundance of Hydronium
ions both from any acid(s) present and from the water, which in the
presence of direct current decomposes into Hydronium (H+) and
Hydroxide (OH-)(hence the bubbles). Direct current passing through
Iron II sulfide will produce Fe++ ions and sulphide-- ions. Hydronium
ions will combine with sulphide ions to produce a covalent compound
Hydrogen Sulphide. Although Hydrogen Sulphide is soluble because of
its highly polar molecule it easily turns to its gaseous state and is
released from solution. (rotten egg smell) This removes hydronium
ions and sulphide ions from solution and promotes the combining of
O-- with Iron ++ ions to produce rust both on the Lapis and in
solution. Worse it would attempt to plate with the setting. Yes fools
gold will conduct and decompose and especially in an anion rich
solution like a plating solution, especially in porous media.Remember
the chemistry experiment of dropping a nail into copper sulphate. The
iron displaces the copper and some Hydronium producing a yellow iron
II hydroxide solution. Remember the plating of metals such as copper
on non conductors like baby booties.

Sorry, its just my retired chemistry teacher resurfacing. My
apologies I am working from memory


#12
Any and all acids have a specific use 

There were a couple of posts… Unless you are using some nouveau
solution, gold plating is cyanide based. As I’ve heard, heavy
plating just about requires it.

There is no acid in a cyanide solution. If you were to put acid into
it you would create a gas chamber (yes, like that one). Cyanide in
itself shouldn’t alter lapis, especially if it’s a hard, solid piece.
I’m not going to argue with some who advocated a conservative
approach, either. But gold plating is usually cyanide based. Rhodium
plating, which is acid based, can etch a lapis, yes.


#13

Thanks for all your replies. It is a nice lapis (from Afghanistan)
and the only calcite I can see is underneath it; I’d hate to ruin it.
I called a number of people all over town and everyone gave me wildly
different answers; I just told the client that it was a no go and
she’s cool with silver.