Green Banded Calcite - Rainbow Banded also known as Inca or Aztec Calcite. They are wonderful healing crystals for you to make part of your life as they have quite powerful attributes and are very easy to use, and are are strong energy amplifiers. By simply holding one in your hand, you can create an amazing flow of energy through your body.
Size and photos are a guide.
Disclosure: If you're worried about your health always see your doctor first. There are no guarantees with crystals, but they may enhance your life.