Sapphire is the gem form of corundum.   The pure red is called ruby, all other colors are sapphires.  Most gem sapphires are blue.  Other colors are called "fancy sapphires".  Padparadscha, a rare orange-pink variety, is more valuable than the blue.  Blue sapphires get their color from small amounts of titanium and iron mixed in the aluminum oxide that forms most of the stone.  Some sapphires are heat treated to improve their color.  Some sapphires with inclusions of tiny, rutile needles exhibit an optical property called asterism. This results in a star sapphire.  Sapphire is the birthstone for September.
 
Folklore and healing properties:

    It is said that the original stone containing the Word of God that Moses brought down from Mt. Sanai was a large sapphire.  The sapphire promotes psychism, love, meditation, peace, healing, power, and money.  It enhances creativity and repels envy.  It removes unpleasant thoughts and negative energy and brings peace to its wearer.   Sapphire improves mental clarity and clear thinking. It clears mental garbage.  It gives the wearer the ability to discern the truth and foresee the future. It is an aid to spiritual enlightenment and inner peace.
It is also considered an antidepressant and an aid to psychokinesis, telepathy, clairvoyance, and astral projection.
    The sapphire is said to reduce fever and inflammation and aid hearing.  It is helpful for burns and some cancers.  It helps rheumatism, colic, and mental illness.  The blue sapphire will mostly aid to energize the throat chakra and organs in that part of the body.