– I have been working with liver of sulfer to create a black patina on
a pair of silver (sterling) earrings. I am having trouble getting
uniform coverage with out streaks.
G’day, Stephane; To get a good black the silver must be scrupulously
clean and grease-free. After washing carefully so as not to scratch the
high polish which you must also have, de-grease the work in acetone which
you can apply (also carefully) with a piece of soft tissue. The ‘liver
of sulphur’ (potassium polysulphide) should be fairly hot, and the work
totally immersed until properly black all over. Rinse well under a tap
and allow to dry - a little gentle heat from a hair dryer helps.
Unfortunately, with constant wear, the black begins to wear off quite
quickly - which is why I don’t like to use it these days, but earrings
don’t get a great deal of rubbing. Have you thought of making patterns
in the black silver sulphide? You can paint the pattern with - for
instance - nail polish after the cleaning job, then get the polish-resist
off afterwards with acetone or nail polish remover. And by the way, the
"lime-sulphur’ solution obtainable in all gardening shops works just as
well as ‘liver of sulphur’ but is far cheaper. But the rotten eggs smell
of both of these chemicals is hydrogen sulphide, and is quite as poisonous
as cyanide, so work in a well ventilated area and don’t breathe it in more
than you can help.
I have also heard that the color pink can be achieved on silver using
liver of sulfer.
If you suspend your earrings above the surface of the hot ‘liver of
sulphur’ in a glass jar, you will see a gradual colour change, from pale
fawn right through to black, and stop it when you have the shade you want.
/ /__| \ @John_Burgess2
At sunny Nelson NZ (in winter)