Apatite is a phosphate mineral in varying shades of blue-green color and occasionally a rare yellow. 

Metaphysically, Apatite helps clear confusion and brings clarity. It helps us to communicate better with others. If you're looking to boost creativity, Apatite is the perfect stone for you as it helps to stimulate thoughts and ideas, as well as bring motivation. Ultimately allowing you to 'think outside the box".

Physically it's a great stone to help suppress hunger and other urges.  It's oft recommended for joint related physical issues as well.