Silver turned gold in pickle

Okay I’m truly baffled. I left a textured strip of 20 guage sterling
silver in sparex pickle over the weekend and it turned gold - looks
like brass. The rest from that particular sheet is fine but I can’t
get rid of the gold color of this one piece. Tried re-annealing,
steel wool and even filed a corner to determine if the color goes all
the way through the piece - it does.

If I scrap this piece and send it in for refining along with my
other scrap will it be tossed out as base metal or included with the
melt?

Thank you!
Cyndy

Hello Cyndy,

Don’t send it in for scrap! Cut it into wires and make it into a
rosary chain. Now that you have announced this miracle to the world
via Orchid you had better brace for a wave of Marian pilgrims.

All the best,
Stephen Walker

Cyndy,…I suspect there may have been a tiny piece of iron in your
pickle and that caused a galvanic condition whereby the ‘gold’ or
’brass’ color (actually copper) came out of solution and plated your
silver.

Don 't try to sand or grind it off. Take a bit of warm pickle, add a
teaspoon of hydrogen peroxide and put the metal in that. Wait for a
few minutes and you should see the silver color return. What happens
is the copper to returns to the pickle solution.

Cheers, Don in SOFL

Years ago I worked at an office when I started metalworking classes
at a local college I had a co-worker at the office that purchased a
rosary at the Vatican and had it blessed there. She used it for a
while and was all excited when it started to turn to gold… I do not
think I ever convinced her it was a thinly plated brass chain and the
silver was wearing off. She is probably still rubbing the chain while
her fingers turn green, another miracle.

I bought the sterling silver sheet from a reputable source and the
rest of it is fine. I just hate to trash this piece and I certainly
want to avoid doing this again. The brass color seems to go all the
way through.

It would be pretty if not somewhat splotchy.

This reminds me of something peculiar happening to me less than a
year ago. I cast several sterling silver links and for a reason I
cannot figure out only one link continues to oxidize into a gold
color. I clean it using pickle, tarnex, and even re-finished the
link however to no avail. After about a week and sometimes less than
12 hours it returns to a pale gold color. Anyone have a clue why? It
was cast on the same tree as atleast one other link, so I am
completely stumped why just this one is strange.

Erica Finkowski
Elf

Hi Cyndy,

There is likely nothing wrong with the silver piece you have made.
More likely another metal - copper, or brass was suspended in your
pickle and plated to the surface as the result of an electrochemical
reaction.

In a well used pickle where more than one metal is present, the less
noble metal tends to bond to the nobler metal. Copper to silver,
silver to gold, etc. “plating” the surface.

If you want to test this, find a piece of copper or some real copper
pennies (most modern pennies are filled with base metal and will not
work), and let them cook in the pickle overnight or if you have time

  • for a couple of days.

Using a pair of steel tongs or steel locking tweezers dip a silver
object in the pickle. The presence of steel causes an
electrochemical reaction which will cause the suspended copper in
the pickle to quickly plate to the silver. Do this in a well
ventilated area because the fumes are noxious.

The plating buffs away easily. If this is not the case, and your
silver has truly turned to gold, please send me your recipe!

Best regards and wishes,

Michael Rogers
M. M. Rogers Design
Albuquerque, NM

As a post script… Silver like other metals changes color as it is
heated, and it may be that your piece just needs a good buff to
remove oxidation, and reddish fire scale (cuprous oxide) from the
surface. However, a long soak in clean, strong, hot pickle should
have returned the surface to matte white.

If a good buff does not return your silver piece to a bright white
finish, you should immediately contact your supplier.

MMR