Gittin 20: Divorce: In Gold or on a Slave

Chiseling or embossing the letters of a get - with the example of the kohen gadol's front piece. Can a get be written on gold, and let that count also as the ketubah? Also, figuring out Rava's position, his argument on himself, and the way a woman might give up the value of her ketubah for a get (not written on gold). Also, what about writing a get on a Canaanite slave's hand - now what?