Black Background for Blue Moonstone?

I’m setting a blue moonstone in 18K gold. However, the blueness of
the stone looks best against a black background. I’ve asked around to
see what I should use for this and have been told either black plexi
or a piece of black plastic trash bag. Is this the best way? I
wouldn’t want to use plastic if I could help it. Any ideas or advice
would be most welcome.

Recently someone wrote in to use the newly ‘fashionable’ black
nailpolish. I have bought a bottle and will be using it soon. Its
easy to find right now because of the Goth style in the U.S.

Sharron in rainy and stormy Kuala Lumpur

Try taking a thin [30 gauge] piece of Sterling Silver and oxidizing
it to a nice black. Put the silver piece in a pin tumber or steel
shot tumbler for a few minutes in soapy water. This will help to set
the color so that it doesn’t change over time. Then back the piece
with this wafer of silver. This is similiar to how folks used foils
in the past to back a stone.

Good luck Dennis


Black pitch is a traditional method of blackening behind a moonstone,
but I prefer to use an epoxy mixed with a flat black enamel paint.
Mix the epoxy, spread it inside the bezel but not up onto the bezel
walls, and wait until it is semi-hard. Then press the moonstone into
the epoxy. Since the epoxy is somewhat firm, it will conform to the
base of the moonstone, but nor be squeezed up along the sides (unless
you used too much). Wait until the epoxy has set, then set your bezel
normally.The bezel is holding the moonstone in place. If the bezel is
not tight, don’t count on the epoxy alone to hold the stone. It


Douglas Zaruba
33 N. Market St.
Frederick, MD 21701
301 695-1107

I'm setting a blue moonstone in 18K gold. 

I’ve done that and cut out a piece of sterling to fit exactly in the
bottom of the bezel then turned it black with liver of sulphur. I
sprayed it (or cover with clear nail polish) so the black wouldn’t
come off if the piece is cleaned.

Donna in VA

Try a black permanent marker.


Put the silver piece in a pin tumber or steel shot tumbler for a
few minutes in soapy water. This will help to set the color so that
it doesn't change over time. 

Cool, I didn’t know that. How and why does that work?


Elaine Luther
Metalsmith, Certified PMC Instructor
Hard to Find Tools for Metal Clay


You could use a product called “chem-blak”, which is a sort of
plastic paint that you cure with heat. It’s made by the Rey company.
I got mine several years ago from Rio but can’t find it in their
catalog right now. Perhaps another supplier carries it.

Jerry in Kodiak

You can purchase black femo at any “craft” outlet. For instance,
here in Connecticut we have Michael’s crafts which is also
nationwide. Or perhaps a store where one would purchase art

It is sold in small 1x1" squares basically. It is like putty or
clay. You can actually do some very amazing artistic things with it
and there are so many colors to choose from. It is another media that
some artist choose to work with…I choose gold, they choose
femo…lucky them, the price is much less expensive. haha :slight_smile:

Hope this helps,


The femo is not baked after we set it in the bezel and before we set
the stone.

We apply a small amount of femo into the bezel, put in the stone and
set it with the hammer held hand piece. Thus far after over a year of
doing this procedure we have not had any problems with the femo
cracking or the opal being damaged over time from our customers.
“Knock on wood”


I’ve found a way to not only put a little color behind a somewhat
translucent stone but also cushion and raise the stone if it’s got a
low dome. It’s Premo. It’s similar to Fimo but fimo is much stiffer
and harder to work with than premo.

This is what I do: First I form the bezel around the stone (I like a
really tall bezel… much taller than the stone should have) and I
solder the bezel together. Next, I stick a small bit of premo inside
and then in goes the stone. I add or take away premo from the
underside until the stone is an acceptable height for the bezel.
Then, I bake the whole thing in a dedicated toaster oven. Premo
bakes at a rediculously low temperature…around 200 degrees or so. I
don’t know if I’d try it with an opal, but I’ve done it with
turquoise and all kinds of harder stones with no negative results. I
usually underbake the premo so it’s nice and soft, but not squishy.
It makes a wonderful “orthotic” for your stone and allows you to
boost your stone up higher for more visibility. Ok, so after it comes
out of the toaster oven, I let it cool and then I’m able to pop the
stone and the formed piece of premo “orthotic” out of the bezel…
file off any edges on the orthotic that might make it difficult to
reinsert when it’s time to set the stone and continue with soldering
the bezel to its base, etc.

I’ve been doing this for two years and have been really happy with
the results. I suppose you could use any color of premo to add more
color to a dull stone… or perhaps PUT color behind a clear piece
of quartz! If you want really funky pearlescent premo, add some
pearl-ex pigments to it… or if you’re into “clubwear” jewelry,
use glow in the dark premo behind a fairly clear stone and your work
will glow under the black lights!

I hope this helps,
Polly Spencer
Mary Amalia Jewelry
Portland, Me.

I really don’t know for sure, I am not a chemist. But I think what
may be happening is that the soapy water, which is a mild base
solution, is neutralizing the liver of sulfur and Silver. This seems
to hinder or stop whatever other chemical reactions that might take
place over time. I have a few pieces that I have gave my wife over
the years that were oxidized in this manner and I noticed one the
other day that still has the glossy blue black that I put on it
about 15 years ago. Something else that I didn’t mention about the
backing is that it is really good to dome the sheet a little so that
there is a cupped area under the stone. I also, drill a little hole
near the edge. You can’t see the hole, the bezel and reflections hide
it. The hole helps to remove trapped moisture and the doming away
from the stone really plays with the reflections of the colors in the
moonstone. I did this with a Aqua cab and the stone came alive,
before it was kind of dead in the mounting.

Good luck Dennis

FIMO is spelled like this, FYI. It is a trademarked name for a
specific brand of polymer clay. Other brands include Kato Clay and
Sculpey. All must be baked in an oven after shaping, usually at about
275 for 15 minutes.

Elaine Luther
Metalsmith, Certified PMC Instructor
Hard to Find Tools for Metal Clay

Stuller carries the chem.-black you are in search .

Andy “The Tool Guy” Kroungold
Tool Sales / Technical
Stuller Inc
Phone 800-877-7777 ext. 94194
Fax 337-262-7791