There are so many different alloys and as you know, each has its
own physical and mechanical properties which are not always
logically predictable. I have worked in two of the reddest 18k
alloys: Au 750 + Cu 200 + Ag 50, as well as Au 750 + Cu 250. In
neither case did I find the metal to be overly brittle or
unworkable. This may be due, in part, to the fact that these
alloys are quenched in alcohol rather than water.