There are many. What color are you after??? If black—brown, liver
of sulfur will do the trick, getting different colors with different
metal, liquid temps and different concentrations (a pea sized chunk
in a cup of water is a good starting concentration to be diluted upon
use, different concentrations giving different colors). This
chemical will darken with age.
Ammonium Sulfide , most any garden sprays containing forms of sulfur
will work for differing gradations of black/brown.
Gun blueing (sporting goods stores) which are mostly formulated for
steel gun parts will almost always work to a good degree on coppers,
try brushing with a brass/bronze bristle brush while the chemistries
are reacting for different colors. Birchwood Casey makes many of the
gun blueing chemicals and also make black and brown coloring
formulas, but normally found by the gallon or more ($100’s per
Urine, copper sulfate, copper nitrate, copper chloride, will give
There are MANY other chemicals and colors available but most all of
them will not ware well on warn jewelry and the body acids and salts
from skin contact will cause blue/greens to develop of warn
contacting the skin.
There are a couple of books on patinas (search on Amazon for patinas)
and availability of mixed formulas from a couple of companies. Check
at some of the good (large) art stores (Dick Blick for one) as they
might have them. Also Sculpt Novou in Escondido Califorina sells
them. Again check the web (I am not near my address file but I know
Sculpt Novou has a web site.