Blue gold leaf

Jewelry Discussion
1

Hi,

I am a self-taught silver jewelry-maker and would like to learn to
incorporate some gold in my pieces. At the current gold prices I
limit myself to practicing on broken/ not worth repairing jewelry
from myself/ friends/ relatives. Since every little thing helps I
also have been trying to recover a nice amount of gold leaf from a
bottle of bath oil I found at the salvation army. The ingredients
listed are several oils, fragrance and 24K gold leaf. It has been
standing on a shelf for years and the gold leaf has turned a bit
bronzy over the time. I decanted the oil and carefully washed the
leaf in regular household degreasers (dish washing detergent,
greased lightning, Mr. Clean etc. - in sequence - not at the same
time) by immersion in a glass jar with water+detergent, swirling,
letting stand for a day, decanting, repeat. However, over the days,
instead of getting bright again, the gold turned green and now it is
an intense steel blue/ peacock green.

I have two questions now for metallurgy-wise orchidians: Based on
the assumption that it is actually 24K gold,

  1. How can I make it gold-colored again?

  2. Since it is a very nice color, I would like to be able to
    understand and reproduce the effect. Do you have any guess what
    happened?

I have not tried to heat and/or pickle it, which would be my next
step. Since the amount is quite small I don’t mind loosing it through
experimentation, any learning experience is worth it.

Thank you,
Isabella

2 
I have two questions now for metallurgy-wise orchidians: Based on
the assumption that it is actually 24K gold,

I’ll bet that the answers to your question are based on a likelihood
of the above assumption being incorrect. Pure gold would not
discolor as you describe. Most likely, the leaf was a gold color, but
not actually gold. Such products are sold for less expensive gilding
work, and are basically brass alloys, if i recall them correctly. No
precious metal.

Peter