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Opal polishing


#1

Hello again, after my long hiatus.

Here’s a question for you old-time jewelers. I have a client for whom
most of my work is repairing very old clip earrings and putting old
necklaces back together. Not much money, but I really like her, and
since she’s 97, I won’t get to work with her much longer. She has
asked if I know about a product she used to use to renew the shine on
her opals. It was a powder or paste that she rubbed on her fingers,
then just rubbed the opals until they were shiny. Does this ring
bells for anyone? If you know the name of the product and if it is
still available, I’d love to be able to pass it on to her. Thanks.

Bev Ludlow
Renaissance Jewelry
wirewrapjeweler.com


#2

Hello Bev,

cerium oxide will do. Make a paste out of this cerium oxide mixed
with clear water and you’re ready to go.

Enjoy and have fun.
Pedro


#3

Quite possibly she might have been using cerium oxide, a standard
lapidary (and also glass) polish; slight surface cloudiness resulting
from shallow and minute abrasions could very likely have been
polished out in this way.

Cheers
Hans Durstling
Moncton Canada


#4

I am not sure what she may have had. There are paste metal polishes
like SemiChrome, Braso or Blitz (not sure of the spelling), all of
which would probably be able to polish opal with, as opal is very
easy to polish compared to most The soft cloth itself,
that you do a final buff with will bring out the shine. You would
need to experiment on a piece of scrap opal to see what works best.

An old optician once gave me a container of Cerium Oxide that I used
to hand polish chipped Waterford crystal. That should work well too,
but I am not sure where you would find it.


#5

Yup. That would be powdered tin oxide. You could do her a favor and
do it for her. Use a small felt buff on a flex shaft. Get the small
buff and the stone wet and apply some tin oxide powder. It doesn’t
take much time to do and the results can be very satisfying. It is
messy however.

If there are deep scratches, they will just get shiny and not go
away. If you want to you can use fine emery to take them out and
then the tin oxide.

Have fun and make lots of jewelry.
Jo Haemer
www.timothywgreen.com


#6

Thanks, all. Seems Cerium Oxide it must be. Perhaps, since my husband
used to work with opal quite a bit, there is some among his things.
May be time to look through & see what’s there.

Bev Ludlow
wirewrapjeweler.com


#7

It was probably Cerium Oxide Optical Grade Polish the MSDS shows no
specific effect on humans so it is something that could be safely
sold OTC. I don’t polish opals (yet) but I do use Cerium Oxide and
have had no problems. It is a nice polish and would work quite well
as you described how your customer used it.

Hope this helps,
Regards
Sandra G.


#8

An old optician once gave me a container of Cerium Oxide that I used
to hand polish chipped Waterford crystal. That should work well too,
but I am not sure where you would find it.

Look up Lapidary Equipment and Supplies and you should find a number
of places that supply polishing compounds: Cerium oxide, tin oxide,
diamond paste, etc.


#9

Hi Bev,

When you look for the Cerium Oxide it looks like makeup being a light
tan or beige color powder. The way I mix it is to put some into a
dish soap container for liquid soap with water and add a few drops of
liquid soap to make it slippery. This way you can shake the bottle
before using it to mix it up, then squirt a small amount on some
soft leather like a shammy that you would use for wiping off your
car. I put a folded towel under the leather to have it conform to the
curve of the top of the stone. Now, mount the stone on a dowel stick
a little smaller then the stone with epoxy. This will make holding
the opal a lot easier to control as you polish it by moving the stone
back and forth with rotating movements’. Once your done you can just
take a jewelers saw and cut off the stone and use a sharp blade to
shave off the rest of the glue.

Good luck,
Mark


#10

Opal Polishing: Cerium-Oxide Powder. Light tan in colour and mixes
with distilled water only, for reasons of absolute purity of mix.

Stephen Wyrick,CMBJ,GG, and the best degree is 41 years of learning
and traveling, (31 countries) this most inquisitive profession


#11

I just found an old Taster’s Choice jar on my late husband’s
workbench labeled, TaDa… Cerium Oxide! Thank you all. I’ll tell
her I found it & offer her some, or do the polishing for her; her
choice. (and could be my first “stone polishing” experience. :slight_smile:

Bev Ludlow
Renaissance Jewelry
wirewrapjeweler.com


#12
When you look for the Cerium Oxide it looks like makeup being a
light tan or beige color powder. 

That’s the so-called “optical grade” CeO. Higher purity material is
white, and preferred by most (but not all) faceters.

Al Balmer
Pine City, NY


#13

Bev, glad you found the Cerium. However, there are a couple of other
things. Use the cerium on felt and pressure light to medium. Do keep
the polishing speed down to about 400 rpm. And, of course, prepare
the stone to near polished state prior to polishing.

Cheers from Don in SOFL.


#14

You can find Super Cerium Polish also called French Cerium at
http://www.ganoksin.com/gnkurl/q6 under Lapidary Tools and
Supplies/Silicon Carbide Grits and Polishes. It is what I use.

If you really want to find out about optical cerium oxide visit
here: http://www.ganoksin.com/gnkurl/q7

As with all powders, remember not to inhale it.
Sandra G


#15

Or for Cerium Oxide you can always go to
http://www.ganoksin.com/gnkurl/qw.

They currently have it in 1 lb cans or 5 lb boxes. Remember, Cerium
Oxide is becoming very hard to get and prices are rising rapidly. I
recommend all lapidaries lay in a stock.

Cheers from Don in SOFL.


#16

This is very much off-topic, for which I apologize. I have some
Waterford crystal gasses which have become fogged - which I presume
is the result of their being cleaned in a dishwasher using strong
detergent and water softened using a salt based conditioner. Would
cerium oxide on a felt buff likely restore the surfaces?

Thanks.


#17

Hi James.

This may be the result of changes to dishwasher formulas lately - no
longer using phosphates.

My (ordinary) glassware was becoming cloudy. Using vinegar in the
wash reversed that problem. I was adding about 1/3 cup to the bottom
of the dishwasher in addition to filling the cup with the regular
dishwasher detergent. If your cleaning cycle begins by pumping out
any liquid remaining in the tub, wait to add the vinegar or it will
be pumped out too.

There are also products made to add to dishwasher if "hard water"
film and spots are a problem. Glass Magic (Finish) is one. It
contains phosphates.

Hope this helps.

Pam Chott
www.songofthephoenix.com