Adding LinkedIcon icon to 'Share this Post'

Hi,

Thank you for creating an excellent theme, it is working like a charm and of course also very aesthetically pleasing!

I have a quick question: I modified _screen.css_ to include _.icon-linkedin_, which I wanted to add to the 'share this post' section of the 'post template'. I changed the Unicode (?) character code to 'f427', but it is not displaying. Is the icon missing in the 'casper-icons.woff', or am I simply using the wrong chracter codes? Thanks!