My one of my professors always wears a large cross/crucifix over his shirt.  I haven't really looked at it too hard but it looks a bit unusual.  The best way I can describe it is that the left, right, and bottom "arms" are about the same length but the top "arm" is extremely short or not even there.  Does anyone know what it might be and what religion it might be associated with?  I've always found it interesting since he always wears it and its larger than most(probably 4" from the left tip to the right tip).

Tau Cross.