aluinAlum is a sweet, water-soluble colorless to white, crystalline double salt of aluminum and potassium sulphate. It is used for tanning leather, staining and fixing of textiles, paper stiffening, and as a water treatment agent (antiseptic).
Known as bleeding stopper for shaving by the contracting action and binding to proteins.

Alum was won primarily in certain mountainous regions of Asia Minor.