This may not be very helpful to YOU, Brent, but others may find it
so: The Finnish master jewelers working for Faberge commonly used an
18K alloy consisting of 75% Fine AU and 25% CU, nothing else.
Very careful annealing was necessary to avoid cracking and
Purposeful fire gilding of this alloy produces an interesting
If you heat the metal to dull red and let it air cool you will see
the copper oxide on the surface. Pickling will remove the oxide and
leave a very thin layer of purer gold. Burnish this gold surface and
repeat the careful heating to dull red, cooling in air, pickling and
burnishing 5-6 times. You will be left with a surface exceeding 20K
and having the same color as 20K gold, and it will be quite hard
from the heavy burnishing. This way, you can create a piece with the
look of high karat, but very durable and it’s still 18K (well, a
That’s not YOUR goal, I know, but the 75/25 mix produces a lovely
Ever seen the museujm tour of the “Gold of the Incas”, all the
goblets and pieces presented as pure gold? They aren’t, never were.