This is a one-of-a-kind ring.  I designed, cut and hammered that skull from flat sterling silver to give it three-dimensional effect and to fit that turquoise perfectly.  This one's equally cool for a woman or a man.
 
Size 9.
 
All sterling silver.  Note that I applied a ceramic e-coat finish to this ring so that it won't tarnish.  The coating changes nothing; it only keeps the silver from tarnishing.