Black Star Diopside presents a beautiful, bright white floating Star, or asterism, on a lustrous black surface. Asterisms are more commonly seen in star rubies and star sapphires. They differ in the fact that the asterism in black star displays 4 points as opposed to 6.
Being a black stone, it is associated with the base chakra. It resonates at a very deep, physical level. It helps to stimulate the more physical aspects of brain function, such as computation and spatial awareness. Black Stars connection with our physical aspects makes it ideal for the gym. I use it on the treadmill myself to keep muscle spasms, stitches and cramp at bay.