I admire you wanting to make your own wedding rings. There is a lot
to consider when doing this, especially with white gold. Do you plan
to make wax models and cast them, or fabricate them, by making an
ingot, and rolling out stock? Panning fo your own gold, I think, is
fantasy. That gold that comes out of streambeds is not pure gold,
you know, and has other elements mixed in, so refining to pure gold
would be advised.
If you buy scrap gold, what kind of alloy is in it? Will it cast
well, or roll out well? That is always a crap-shoot, and you are
lucky if it will do what you want.
Go with pure gold and an alloy that is made for doing what you want
to do with it, and the color you want it to be. Personally, I don’t
use “casting” alloys, except for special cases. You can’t roll it
out, because it is too brittle. If your scrap gold has ANY casting
alloy in it, you won’t be making an igot and rolling it out.
A traditional white gold alloy has been nickle based. Cheap, but
brutal to roll out. Many complain about it not being white enough,
requiring rhodium plating (which I don’t like to do). However,
palladium as an alloy for gold is wonderful to fabricate with, has a
great white color, but is pricey.
You might want to consider working in palladium if you are on a
budget. Easy to work with, great color, about the same price as 14k
gold. Your silversmithing techniques should serve you well when
working with gold, but I’d get some dark lenses for melting the
palladium and palladium alloys, and if you want to work in platinum,
do your homework, as it requires much more care and eye protection.