first of all, i should say that its an excellent poem. there was only one thing that bugged me a bit and that was the fact that you go from comparing something to stone, then to glass, and then the last two to ice/cold.
my suggestion would be to either make all of them something different, or make them all the same. personally i like the idea of all of them being different because
"I can't make flesh from glass"
was by far my favorite line.