Throwing axes in the SCA come in many different styles from french style to the tomahawk-style axes used by many. What differentiates a throwing axe from a normal axe is that it is designed to be thrown. While one can throw any axe and get it to stick, the throwing axe is a semi-balanced weapon that can be thrown more accurately.
Here is a french style throwing axe. 
I do not know if it was thrown, but here is Utzi Man's axe. 
Here are a pair of axes are also commony seen being thrown. 