Depletion formula

A long time ago a formula was given to use ammonium chloride,
aluminum potassium sulfate and potassium nitrate to boil 18kt gold in
to bring up a high karat color on the surface. I have the chemicals
but can’t find the formula. Would appreciate it if someone has that
formula. Thanks in advance.

Richard Hart G.G.
Denver, Co. 80210

Richard,

Charles Lewton-Brain published an excellent paper, complete with the
necessary formulae for cementation and depletion:

Mark Bingham
Fourth Axis

Richard, would you mind explaining why or when you would use this
formula?

Thank so much.
Angela Hampton
Hampton House Jewelry

A long time ago a formula was given to use ammonium chloride,
aluminum potassium sulfate and potassium nitrate to boil 18kt gold
in to bring up a high karat color on the surface. I have the
chemicals but can't find the formula. Would appreciate it if
someone has that formula. 

Original post was about restoring finish in places that cannot be
reached by mechanical means. No chemical formulae is going to work
for this particular situation.

We using terms like rose gold, green gold, and etc. The actual color
of these alloys are far from rose and green mean in everyday life.
The hue differences can be made obvious, but it requires very high
degree of polish. If surface has been depleted, it lost it’s polish,
and while depletion layer can be chemically removed, the finish
cannot be restored this way, and hue differences are not visible any
longer.

In working with more than one color alloys, the trick is to preserve
finish though all the soldering steps. There are no shortcuts
available for this. The design and fabricating sequence must have
provisions for finish preservation.

Leonid Surpin

Richard, would you mind explaining why or when you would use this
formula? 

The process is used to bring up the high karat color of gold 18kt and
above. I bought the chemicals mentioned and misplaced the recipe.

Richard Hart G.G.
Denver, Co.