1st poste here 
I mainly use pocket knives with simple stainless steels. Think Victorinox and Opinel steel. What would be my best bet for a pocket stone for general maintenance? I am not looking for bench stones or complicated sharpening systems, just a small stone. Any pros or cons to ceramic, natural or diamond stones would also be appreciated. And what grit would be ideal? Thanks!

I mainly use pocket knives with simple stainless steels. Think Victorinox and Opinel steel. What would be my best bet for a pocket stone for general maintenance? I am not looking for bench stones or complicated sharpening systems, just a small stone. Any pros or cons to ceramic, natural or diamond stones would also be appreciated. And what grit would be ideal? Thanks!