Depends on your gem type. If you're a Peridot like me, you fix things, or you work on growing other gems. Or both, in my case. It depended on where I was needed, or where Yellow Diamond ordered me to go.

At least, that's what I used to do before I got stranded on Earth. Now I live in a barn with Lapis and watch Camp Pining Hearts and make meep-morps! Er, when I'm not working here, I mean.