I am taken from a mine, and shut up in a wooden case, from which I am never released, and yet I am used by almost everybody.
What goes round the house and in the house but never touches the house?
What is it that you can keep after giving it to someone else?
What walks all day on its head?
A nail in a horseshoe
What gets wet when drying?
What comes once in a minute, twice in a moment, but never in a thousand years?
The letter M