Answer:
Taken from a mine and then locked up in a wooden case. I am used by students everyday.
I can be cracked, made, told, and played. What am I?
I am put on the table, cut, but never eaten. What am I?
I am black when you buy me red when you use me when I turn white you know itβs time to throw me away.
A trail, a union, together tied. Come across me and you will find you cannot change the course I'm on. Without me you cannot travel on. What am I?
If itβs information you seek, come and see me. If itβs pairs of letters you need, I have consecutively three. What am I?