My mom is a chemistry teacher and found a glass tube containing mercury and blue crystals, what is it?

Question

its less than a foot long and completely sealed in glass with one end pointed. it has mercury and some weird fragments of what looks like a blue crystal but it could be gel. i have no idea what it is but my mom found it in the chemistry class she teaches and was supposed to get rid of it because it contained mercury.

Answer 1

Maybe an old delay timer???  Hard to tell without seeing it but very old computers used to have mercury and quartz delays using a glass tube with quartz crystals and mercury...