Depletion Gilding 22 karat gold

Jewelry Discussion
#1

Greetings to the fine folks of Orchid,

I have read all the archives but still have a question.

In my workshop we work in 22 karat gold which we alloy ourselves.
A woman taking my workshop wanted to bring a richer, deeper yellow to the surface of a thick 22 karat gold chain.

We heated and pickled three times and the gold got whiter rather than yellower. My student was not happy. :0/ What did I do wrong? Looks like all the silver came to the surface rather than the gold. How can this be reversed?

Maybe it happened because;
We didn’t use the soft brass brush between each heating.
We didn’t heat the gold enough.
We used strong Pro-Craft Pickle which I believe is sodium bisulfate.

Trying to avoid using toxic chemicals.

When I studied at Jewelry Arts in NYC we did this all the time with the regular pickle and my notes say … heat and pickle three times.

Any and all help would be greatly appreciated.

Thank you.
Warm regards,
Lois

2 Likes
#2

My first suspicion would be that the bracelet is actually sterling silver, plated with 22k gold. Easily checked with a small triangular file and a precious metal testing kit.

1 Like
#3

To give a sensible answer first we need to know what alloying metal or metals do you add to the gold, and in what proportions.

#4

Greetings, thank you for responses.

To alloy to 22 karat gold we take:

31.1 grams of 24 karat gold .99999 pure

Add:
0.71 grams of pure copper

2.13 grams of fine silver

to make 22 karat yellow gold.

We check the 24 karat gold that we buy refined from my trusted supplier, melt it and check for crackling and a depression (hole) mark which indicates it’s 24 karat.

I am reading that I was supposed to use a fine brass brush after each round of heating and pickling ……I did not do that.

Appreciate your comments.

Thank you.
Kind regards,
Lois

1 Like
#5

copper gives gold a redder deeper color. silver makes it green gold. heating and pickling is oxidizing the copper out and leaving it paler than fine gold. the silver is also lightening it some. Krugerrands are 22 ct. gold with the remainder being all copper. melt them down for a richer gold. The gold bullion value of Krugerrands are not overpriced to thier mint value…

1 Like