The crystals that you choose as your bracelet will work with your energy field. One teacher I was fortunate enough to have lessons with, Michael Gienger*, stated that the power of a crystal to generate light interacts with the cells of the physical body.
What is clear is that crystals have an energy field that interacts with any other energy field near it. The interaction of the energy field of a crystal and a human being can, for example, be photographed with a Kirlian camera. Crystals have minerals in their composition traces of therapeutic minerals that pass across the skin barrier to bring about physiological changes. Kunzite, for example and Lithium Quartz contain lithium, which is used by doctors to medicate depression and bipolar disorders. Crystal users hold Lithium Quartz and can feel calmer or uplifted immediately.