Easier said than done.
I did manage to slap down on the list a stone can cause flight, even with the critic observing that I would not, in all probability want to use so metaphorically unsuitable for a stone to do.
But it still managed to steer me down the channel of what sorts of powers are metaphorically suitable for a stone. Impervious, of course. Duration, of course -- and why would you need something so crude as an ice stone to preserve your food when you could use a duration stone? -- unless, perhaps, you were poor as dirt.
And it managed to glean other deductions about the limits of stones. They can't transform things. They can't create things from a void. Many of them need to properly situated to work. If you have an opening stone, you need to set it in the haft of a key, to do it job.
And a flight stone, perhaps, can be discerned by holding the crystalline stone to the light and seeing the form of wings inside its half-clear, half-cloudy heart. . . . muses sometimes are thrilled by challenges