How do I completly remove jekyll, ruby, and all ruby gems?

I don't know much about ruby.

I was trying to get jekyll running on this computer a few months ago. I remember that I installed jekyll and several ruby gems following different tutorials and without taking proper notes. To add to the confusion, only some of it was through apt install. Some of them were gem install.

I want to try again, and I think I'd be better off with a blank slate to start with. As I'm not currently using ruby for anything else, I'm happy to remove it. But will this also remove all ruby gems?

rvm implode

Command 'rvm' not found, but there are 19 similar ones.

sudo apt purge ruby has removed a lot, but I don't know whether gems are still around.