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Stones question?


#1

Hi everyone - Just a couple of questions:

1 - I have a stone that I bought a couple of years ago that I’m
trying to figure out what it is. It is a cabochon that is pale, pale
blue or even lavender. It is also tanslucent with opaque bands running
through it. Would it be blue chalcedony?

2- In trying to clean up a bezel with sandpaper after the stone
(moonstone) was set, I managed to hit the stone with the sandpaper.
Scuffing the stone was the result. Is there any way to remove the
scuffs? It is set in a bracelet with 2 other stones - Lapis Lazuli
and the unknown stone mentioned above. I have a rotary tumbler with
steel shot - could I use this without damaging the stones?

Please help! Thanks in advance - Sarah in North Carolina


#2

Sarah, Do NOT put those stones into the tumbler with steel shot!!

Especially since you do not know what they are there is a very real
danger of scuffing them badly or breaking/chipping them at worst. It
is impossible to tell what the blue/lavender stone might be from just
a description. It could be any one of a dozen stones. The more
important thing for you to concentrate on is the hardness of the
stones and are they grainy or ‘tight’ grained. Re hardness, the lapis
lazuli (lazurite) is 5-5.5 Mohs while the moonstone is 6-6.5 Mohs.
Chalcedony by the way, is about 7 hardness. You already have a
significant difference. If you can get to the unknown stone from
behind, do a scratch test to see what it might be.

You can try polishing out the sandpaper scuff with ZAM which will
simultanteously polish the bezel. Try to stay away from the lazuli
and the other stone unless you know what it is. If all else fails,
you might reduce the scuff by rubbing some beeswax across it or even
carnuba wax. Be sure to declare that if you are intending to sell it.

Cheers and good luck from Don at The Charles Belle Studio in SO FL
where we got 2 inches of rain yesterday and where simple elegance
IS fine jewelry.


#3

Absolutely do not use the tumbler with steel shot on the piece. You
will absolutely damage the stones.

Daniel R. Spirer, G.G.
@spirersomes
www.spirersomes.com


#4
It is a cabochon that is pale, pale blue or even lavender. It is
also translucent with opaque bands running through it. Would it be
blue chalcedony? 

It could be blue chalcedony. It could be Holley agate or purple
chalcedony. And, with those opaque bands, it could be blue lace agate.
It is impossible to tell without seeing it and, even then, if the
origin is unknown, it might still be impossible (since, for instance,
Holley agate technically comes only from Holley, Oregon, but looks
very much like purple chalcedony which often comes from Africa). Then
again, it could be something entirely different like a blue moonstone.
Can you post a picture on a website? That way, I or someone else
might at least be able to narrow it down.

Beth


#5

it could be ellensburg blue, a sure sign is a reddish yellow glow
thru the stone. the blue is based on iron ion #4. that’s what gives
it rarity and value. ringman


#6
2- In trying to clean up a bezel with sandpaper after the stone
(moonstone) was set, I managed to hit the stone with the sandpaper.
Scuffing the stone was the result. Is there any way to remove the
scuffs? 

A couple years back, I had a friend came in with a pair of earrings
she had made for entering the Spectrum awards competition. They had
moon stones of the finest quality I had ever seen. She had scratched
one in the process of bezel setting it and wanted me to polish out
the scratch. Well, Moonstone is a Feldspar and it has one perfect
cleavage and one distinct. All efforts to clean the “scratches” only
opened up the cleavage cracks more. We got to the point of just
accepting that they had a “Flaw” and she put them into inventory
rather than enter them. What a shame as they were an award winning
design.

So the answer to your question is Maybe? Under no circumstances
should you put it in the tumbler though. That will only damage the
stones more.

When you cut and polish a stone, you go through a series of
progressively finer grits and polishes until you have the finish you
want. To repair a stone, you have to start the progression at the
point of damage. IE, if you scratched it with a 180 grit, you have a
lot of work to do to work out the damage. If your “Opps” was with a
finer grit, say 600, then you are in a better shape to fix the
problem.

Take a critical look at the “scuffing”. What grit sandpaper were you
using? To remove the “scuffing” you will have to sand it out and
then polish. Start with the next finer sand paper than the one that
caused the scratches. Make sure you are using Wet or Dry. Work the
stone with the paper wet. When you can no-longer see the original
scratches, move to a finer paper. After working down the stone with
a well worn 1200 grit, then you can start to polish it. When you
polish, use a piece of soft leather, elk, deer hide, or chamois works
best. Glue it to stick with rubber cement. After it is dry, soak
the leather with water and then apply some Linde A or optical grade
Cerium Oxide and start to polish out the stone. This is all done by
hand. NOTE that the Cerium will find any crack and lodge there and
leave a very noticeable flaw. The only way to resolve this is to
sand it out and start over. The Linde is more forgiving but doesn’t
give a nice a polish as the cerium on soft stones.

Now that you know what is needed to fix your stone, here is my
suggestion. If the stone is not very expensive, replace it if you
can. If you can’t find a replacement, you have little to loose in
trying to salvage the one you have. It is already damaged. Just
understand though that it might look worse than it does now when you
are finished.

Don


#7

All, I have a low tech answer to this problem of a cabochon scratched
near the bezel. Use a popsicle stick and 14000 diamond paste. Apply
the paste to the popsicle stick and rub the stick against the stone.
It will take a while, but gradually the scratch will polish out.
Another way is to make a wooden wheel for your flex shaft.
Impregnate the wheel with 14000 diamond and use it next to the bezel.
Everything else we have tried has managed to damage the bezel or
ruined the stone. I have used wood on everything from sapphires to
opals. It works. Gerry Galarneau


#8

HI Don Rogers, I once altered the surface of an Opal, (scratched it!)
didn’t want to remove it or replace it( my expense). So what did I do?
I got my Pink (very fine) pumice wheel and gently smoothed down the
surface, It is graded at 1000 grit! After a few nerve wracking
minutes, the whole scratch wasn’t there anymore! It passed the
"quality control" and saved me a “few” hard earned dollars. I actually
started with a 2/0 polishing paper, then a finer 4/0 paper,…then
the rubber wheel. Each time getting a finer texture of grinding
apparatus! What I did do, was to resurface the entire area and had
the stone mark blended in to the outside area. SO MY cleaning area now
comprised of the scratch and the out laying surface also! gerry, the
cyber-setter… www.gemzdiamondsetting.com