An Alum Block is a crystal-like stone that is moistened with cold water and gently rubbed over the shaved area to act as an antiseptic for razor burn. It can also help to stop bleeding of small nicks and cuts. The Alum block also has antiseptic properties that not only cool and refresh the skin after shaving, but also act as a balm. Simply wet the block, rub gently onto the shaved area, and then leave to dry on the face. If you are applying a moisturiser or after shave balm, splash water on the face, pat dry with a towel and apply your after shave balm or moisturiser.