I could swear I read on the site that you can purchase stones with justice points? I have tried looking on wowhead but can't find where the vendor is, nor can I find it ingame. Any suggestions? Thanks!
To be honest they're there to burn JP. It does give you an option to clear out any greys you have, e.g. Minfernal (if you were lucky enough to find one), or the Cricket from Sho if you got unlucky like me.