You don’t need to use aqua regia to get this surface. Being that aqua
regia is so so dangerous; the off gassing can burn your lungs before
you know it.
USE iodine. Go to the pharmacy and buy pure iodine. I don’t know if
it is really pure but it is not the little bottle that you buy for
cuts. Ask your pharmicist about the safety hazards. We ordered it by
the gallon for about $40.
Here is what you do, and be sure to have ventilation on full blast.
It is not as dangeous as Agua regia but don’t take chances with your
lungs and eyes.
1 Have the piece finished, no knicks scratches etc.
- Clean piece.
3 heat up a beaker of the iodine about one inch deep should be
enough, on a hot plate to about 160 + degrees.
4 put in piece strung on a wire of 14 carat or other gold wire that
you have around.
5 experiment as to how you want to leave it in, try 30 seconds and
then longer,to start until you like the look.I am sorry but I can’t
remember how long we did leave it in for the really storng look. We
did this a couple of years ago.
6 rinse in sink under water.
7 use a little soap and water just to be sure all of the iodine is
gone.
8 Viola’ you have gold crystals.
The structure on the crystal growth on the piece is dependant on what
the stucture was when cast. You will get different results as to size
of structure everytime a piece is cast. There is some liturature that
states that you can increase the gold crystal size by heating the
finished piece in a kiln for several hours at a relatively low temp.
It is all in the archive, you can look it up. However, I never had
any luck when I tried it.
This look can be very striking but it is somewhat ephemeral. It can
scratch easily and kind of wear away. If you leave it in the iodine a
long time you can get pretty deep into the gold. and then it is
pretty permament. we had a couple of pieces that had really deep [.1
maybe.2mm deep etch] that were amazing.
It doesn’t have to have that dull kind of dusty look either. We
experiemented with pin tumbling and all sorts of polishing
techniques to brighten up the surface.
You can do it to lower carat golds but you end up with the dull ,kind
of corroded surface. Sometime people do it to 14 and 18 carat gold to
make it look really old.
Good luck, D