“Shoes for Departure”, an art piece by Marina Abramovic (1991). In her artist statement she says, “Then I have crystal shoes. I have instructions for the public to take off your shoes and, with naked feet, put on the two crystal shoes, close your eyes, don’t move, and make your departure. I’m talking about a mental, not physical, departure. So the public can enter certain states of mind helped by the material itself. Material is very important for me. I use crystals, human hair, copper, iron. The materials already have a certain energy. ” (credit)