The Sapphire is the Birthstone for September. 

The sapphire gemstone is the usual name for transparent corundum. The sapphire comes in the colours of blue, pink, clear, green and purple.  The most available sapphire being blue.  The sapphire hardness is 9.0.

Sapphires are said to enhance mental clarity and heal the mind.  It is the gem of the fidelity and of the soul. 

Sapphire is also the 5th, 45th and 70th anniversary gemstone.