Peridot is a green gem stone.  It's the birthstone for August and is a recommended gift for the 16th anniversary.  The best peridot comes from Arizona, Burma, Hawaii, Norway, and the islands of the Red Sea.  It has been mined for thousands of years. In the Bible, it's called Chrysolite.  
    It was supposedly a favorite of Cleopatra and some of the "emeralds" in her royal jewelry was actually peridot.

    In folklore, it is said to bring peace, good luck and success to the wearer.  It calms anger, sooths nerves, and is a sleep aid.  It is an aid in making friends.  It is said to aid overall health and increase vitality.  As a green stone, it energizes the heart chakra and aids in healing problems in that area of the body.  In mystic lore, it is said to help make your dreams come true.