Adam-- you must quench rose gold while it’s still hot-- just as it
loses red, water quench is fine. If you let the metal cool without
quenching, it will become so brittle that it can break into pieces
when you hammer it. 18K is more prone to this problem than 14K–
just the way the molecules line up in the alloy. If you are not sure
if it was quenched properly, suggest reheating it to red hot, quench
when the color disappears.
Jim Sweaney
mardonjewelers.com