In Asia, it is common for Asian women to whiten or bleach their skin as it is a huge beauty standard.
Alum in the form of or in a concentrated bath of hot water is regularly used by jewelers and machinists to dissolve hardened steel drill bits that have broken off in items made of aluminum, copper, brass, gold any karat , silver both sterling and fine and stainless steel.
Native alumen from the island of appears to have been a mixture mainly of alunogen Al 2 SO 4 3·17 H 2O with potassium alum and other minor sulfates.