What Am I?

What is black when you buy it, red when you use it, and gray when you throw it away?

What can run but never walks, has a mouth but never talks, has a head but never weeps, has a bed but never sleeps?

What has a neck but no head?

What has keys but no locks, space but no room, and you can enter but can’t go in?

I am taken from a mine, and shut in a wooden case, from which I am never released, and yet I am used by almost every person. What am I?

What has a head and a tail but no body?

I follow you all the time and copy your every move, but you can’t touch me or catch me. What am I?

What has 13 hearts but no other organs?

What has a face and two hands but no arms or legs?

Take off my skin and I won’t cry, but you will. What am I?