The question as previously posed was, "Could one use gold foil with
PMC to make mokume gane?" If you were thinking of this process using
fired PMC, it would not work because the foil and the PMC would both
break apart. If you were thinking of this process using unfired PMC,
the gold foil would not stand up to being manipulated and would burn
up in the kiln (it's just too thin for firing with PMC). One could
layer fine silver and fine gold PMC, prior to firing and carefully
rolling, without combining the two materials, might produce a
pseudo-mokume gane, but without the truly distinct patterning for
which mokume gane is appreciated.
All that being said, mokume gane is the result of a fine traditional
process. I love working with PMC, but would not try to reproduce the
look of mokume gane in metal clay. There are so many ways to
manipulate PMC and there are just some processes that do not use
PMC (or other metal clays) to their best advantage.