Lava Shells are Tiger Clam shells found mostly in the South Pacific and Philippines. The shells contain a variety of natural minerals and essential oils which; when heated, give off calcium ions which transfer to your skin during the massage. These shells can radiate heat for up to an hour providing a continuous warm full body massage. As a result, the body's muscle soreness can be relieved and the body radiates heat from the inside out, allowing for unprecedented relaxation.