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Easy diamond removal


#1

Does anyone have any suggestions for removing small diamonds from
scrap gold mountings? I have been buying scrap gold from customers
for
some time. I try to remove all the small diamonds (quarter pointers,
half pointers, one pointers mostly) before sending the gold to the
refiner. Sometimes some of them are so embedded in the mounting I
just let them go–along with the gold. Some of them I break, some go
into the carpet, but that’s OK, I’m getting quite a collection. I use
a combination of techniques to get them out but would like to hear
suggestions from you for removing them.

Thanks in advance.
Dale Pavatte
Diamonds For You
Decherd, Tennessee


#2

Dale,

Hoover and Strong will remove stones from your gold scrap before
melting it.

Steve Brixner


#3

Try dipping the ring in boric acid, then melting the ring or other
piece before you send it in. The stones will rise to the surface like
debris and you can pick them out from there. It’s going to be melted
anyway.


#4

Try using the Aqua regia process, however do not immese the item for
a long time,also clean the mounting thoroughly, the removed diamonds
can be strained off and once again washed under running water to
remove the acid traces. We have been using this method sucesfully to
remove small pave set diamonds, and the gold can be recovered by
sending the aqua regia for refining. Hope it helps.

K.H.Kotwal


#5

Hi Dale,

I sharpen an old bur shank and punch them out from the back. Try
using a dapping block to catch them on the back side. Diff size holes
are good for diff size pieces. Keep what doesn’t break. I give the
chipped ones to my dia cutter. Dias are tough they usually hold up.

Mark


#6

Maybe melting the gold and picking them out of the dish before
dumping it in a mold. I think diamond can take the heat??? But I
could be wrong.

Jen


#7

Dale,

I use a prong lifter. The tool has many slots and several angles that
will slip under the prong and lift it up. Check with RioGrande and
see of they still carry this tool. I paid about $6 for mine and I use
it all the time. I haven’t had any problem lifting any prong since I
started using it in 1995. The tool is about 5 inches long x.5 wide x
1/16 thick. It is steel.

Veva Bailey


#8

Dale, Firecoat the pieces and melt them. The dianonds will come to
the top. Lel it cool, and pick ihe diamonds off.The firecoat will
protect the diamonds to around 1800 deg.

Harold


#9
I sharpen an old bur shank and punch them out from the back. Try
using a dapping block to catch them on the back side. Diff size
holes are good for diff size pieces. Keep what doesn't break. I
give the chipped ones to my dia cutter. Dias are tough they usually
hold up. 

Yup. That’s what I do Mark, as mentioned in my other post. Old burs
are good for the very tiny holes, but I find the hard steel sometimes
breaks a few more of them. I prefer, if the hole in back is big
enough, a somewhat annealed, well, not quite, but tempered to blue
color, small sized beading tool. You make sure it’s placed right on
the culet before pushing. Hard sharp push with the hand, not a
hammer, and almost all survive.

I don’t use the dapping block, though. It’s too rigid. Some diamonds
bounce out, other times, it’s a bit harder to hold things securely
against the steel. I guess I just found that a bit cumbersom. What I
did is to take a bench pin, drill a couple small holes all the way
through. Under the pin I taped a small plastic box bottom. One of
these days I’ll get around to actually making a bracket so that box
becomes a sliding tray. Either way, the wood bench pin is a gentle
surface softening the shock of shoving hard on the diamond, which
falls through the hole to the little catch tray. Easy, and a sturdy
work surface. Before I made that special pin, I used another with
just a dimple, or the V cut, and a cloth spread in the bench pan to
catch the stones as they fell. That too works fine.

Peter


#10
Hoover and Strong will remove stones from your gold scrap before
melting it. 

So far as I know, Hoover and Strong, like other refiners who offer
this service, don’t actually remove the stones at all before
processing. They just skip the initial step of melting it to an
ingot, or spread out shot, or whatever form they might ordinarily
melt the scrap into for assay. Instead, they just go straight to the
aqua regia, which removes the gold from the diamonds automatically,
leaving them in the sediment at the bottom of the beaker. The other
big difference is that your refining lot is handled individually,
rather than being assayed and the settlement being done just from
the assay. That means you can’t use of the quick turnaround
settlement options, if your refiner has such options, since the
entire refining operation has to be done before you can be paid. But
that’s often what you might be doing anyway.

Peter


#11
Dale, Firecoat the pieces and melt them. The dianonds will come to
the top. Lel it cool, and pick ihe diamonds off.The firecoat will
protect the diamonds to around 1800 deg. 

Not all the time, it won’t. If you were to get consistantly good
recovery of undamaged diamonds this way, I’d have to say you were
bucking the odds big time. Out of curiosity, I tried this some time
back. Decent quality melee, very well cleaned, lots of boric acid
firecoat. Five stones. Two were fine after. One badly burned to a
whitish surface. Two visibly less bright, no longer matching the
original polish. Not a good sucess ratio. And if there’s even a
trace of dirt on the stones, forget it. They’d be toast. Well, Ok.
Some of the 10K and 14K yellow alloys melt low enough you might get
away with this. Sometimes. But don’t try it with 18K. And I’d guess
many of the white golds wouldn’t work either. That sample I mentioned
above was 14K white gold…

For removing small melee in pave or flush set, or similar setting
styles without a lot of metal holding, you can often remove them with
just a sharp push from the back, if their drilled through under the
stone, as is usually the case. A beading tool placed over the culet,
and shoved hard with the hand removes most. No hammers, please.
That’s too much. If it doesn’t come out with a sharp push, you need
to cut some metal away first, but from the description of lots of
teensy stones, this method is fairly quick. I know this sounds risky,
but it’s less than you’d believe. While the girdles of diamonds can
be fragile, and a sideways blow to the culet can chip it, direct
pressure straight at the culet is addressing a very strong direction
in the diamond. Consider that scientific equipment used to study very
high pressures, which often is done with diamond “anvils” For all
intents and purposes, that amounts to pressing two diamonds together
at the culets, and watching, through the diamonds, the results on
whatever is between. The culets don’t chip. Yes, you may break a
few, but likely those will be the highly flawed junk melee anyway. I
find I break fewer melee taking them out this way, than I do if
cutting away beadwork with a graver to take them out.

Lots of stuff is set in channels. In rings with channels running
paralell to the finger, just clip the shank at the bottom, and bend
the whole ring to a smaller diameter. That makes the channels wider,
and the stones just fall out. Often, other types of settings can
similarly be just bent, usually after cutting some supporting
structure with nippers, to allow the stones to fall out of the
loosened setting. Much easier than trying to cut away or bend back
the holding metal.

For prongs, prong lifters of prong lifting pliers are fine if you
wish to save the mounting. If you’re scrapping it, sharp side cutters
can clip the prongs below the girdle faster and simpler than pulling
them back. Some flush cut side nippers make very good prong pullers
too, doing double duty.

But even quicker is to NOT remove them at all. Assuming you’re going
to scrap out the metal, simply send the stuff as is, with diamonds,
to your refiner. Most good ones offer the service of acid refining
the jewelry directly, without first melting. You wait longer for
settlement, since they are actually refining your metal to order,
rather than assaying it and paying from the assay. The acid
dissolution removes the gold into solution, and the diamonds,
completely unharmed, can be recovered from the sediment left at the
bottom of the beaker with little effort, and no risk to the stones.
Not all refiners off this service, but many do, and though there’s a
little higher cost for it, it saves all the time, and occasional
chipped stone, for manually removing the diamonds. Some colored
stones can be left in the jewelry too, though of course not all.
Anything not bothered by aqua regia can be treated this way.

This method is probably not needed when you’re dealing with larger
melee or individual larger stones, since with just a few, it’s easy
to take them out and then you’re done. But with the inexpensive stuff
that’s set with hundreds of tiny junk diamonds, or for that matter, a
lot of small good quality stones, this is a cost effective way to
deal with it.

Peter Rowe


#12
Maybe melting the gold and picking them out of the dish before
dumping it in a mold. I think diamond can take the heat??? But I
could be wrong. 

I like Jan’s plan. Just melt the stones out. Fakes will probably
have survival problems :slight_smile:

jeffD


#13

They call these breakout diamonds and for good reason. If you’re
talking about halfpointers and smaller they will mostly be bead set.
I’m not convinced of the efficiency of saving a stone that might cost
you $1.79 to just buy when you need it. Mostly I use a thin cutoff
wheel,.009". Cut in at the appropriate angle and twist the mounting
with pliers. Breakout.

On heavier mountings and larger stones use a heavier cutoff wheel,
…016-.025" and basically grind the tips away instead of cutting
thru the underbezel.

If you try using a jewelers saw you will go thru a lot of blades and
further erode efficiency because it will take forever.

For those that might not know, cutoff wheels only work with diamond,
anything else will be damaged.


#14
Maybe melting the gold and picking them out of the dish before
dumping it in a mold. I think diamond can take the heat??? But I
could be wrong. 

I’ve never tried melting the metal away from the diamonds, but one
potential problem that comes to mind are any inclusions that may be
in the diamonds.

The diamonds may be able to stand the heat of melting, but the
inclusions may not. You may end up with some high priced fish tank
gravel.

Dave


#15

Usually we remove any prong work with a separating disc or a saw
blade and then poke 'em out. The dias aren’t damaged by the disc or
blade. But it’s a pain no matter how you do it. We are faced with the
same issue. I know some refiners will return your melee for a fee,
but the two guys that we like and have used for years don’t offer
that service. I’m thinking about pressing them on it however.

Interestingly, a well known refiner told me that they are getting so
much gold to refine that they are unable to liquidate it fast enough.
They said refining is way up and gold purchases by jewelers are way
down (they all want the cash rather than gold), it’s an interesting
problem. I’m surprised the gold price has stayed so high for so long,
I guess it goes to show you how little jewelry business trends have
to do with the price of gold.

Mark


#16
I've never tried melting the metal away from the diamonds, but one
potential problem that comes to mind are any inclusions that may
be in the diamonds. 

I thought we were talking about Canardlies (Can hardly see them)
Dias. I don’t think that inclusions would really matter in a $1.50
stone.


#17

Cool Peter,

Thanks for the tip on the better mouse trap! I’m going to give it a
try. Should beat the “search” for the ones that get away.

I prefer to punch them with a bur sharpened to a wedge shape and use
a hammer from the back. I stay away from the culets.

Mark


#18
....gold purchases by jewelers are way down (they all want the cash
rather than gold), it's an interesting problem. I'm surprised the
gold price has stayed so high for so long 

A recent article on KITCO dot com stated that India, the world’s
largest gold consumer, has fell from a usage of around 1100 tons per
yr, to aprox 400 tones per year and fear that number may fall as low
as 100 tons due to record high prices. Recent reports say that
during a recent ‘wedding season’ in India, where gold is given to
brides in considerable quantities that most dealers were reporting
unusually low demand for gold. Currency exchange rates(low dollar
value) are blamed as the main reason. India is also a very large
exporter of finished gold jewelry to the USA and other countries, and
recently, export demand has dropped to a small fraction of previous
levels.


#19

Hi Steve,

I thought we were talking about Canardlies (Can hardly see them)
Dias. I don't think that inclusions would really matter in a $1.50
stone. 

I agree! If we’re talking about Canardlies, why sweat the small
stuff?

Dave


#20

This thread is just in time! Yesterday I had a customer come in to
participate in recasting her old jewelry into new wedding rings for
her and her husband. The stuff she had was loaded with "Canardlies"
I just snipped out all the settings, gooped them up with flux and
melted the bits on a charcoal block. All the little diamonds just
went to the surface with the flux and I pickeled them off in a
stainless steel tea infuser. The only thing hard about it was
getting them all under control when they were wet from the rinse,
which involved picking them out of the little basket with tweezers.
There was really nothing to it and I did this for the first time with
the customer watching over my shoulder. I removed about 30 little 1
to 2 point diamonds this way from 5 pieces of jewelry in not much
more time as it has taken me to tell about it.

Thanks for the great tip!
Stephen Walker