This is a gray stone ring with no adornments. 

Once per long rest, as an action, the wearer of this ring can turn to stone and become a statue for up to 24 hours.  You can hear and see, but you can’t turn your head or move your eyes.  You can dismiss the effect at any time, and it takes a turn to revert back to your normal form.  Any damage taken as a statue will carry over (an arm broken off, you will return with no arm, etc)