Living Stones (Lithops aucampiae)
That's such a great photo. They do, indeed, look like rocks. No wonder they were overlooked for so long by horticulturists.
In the home, do Living Stones need a southern exposure window? Can they be successfully raised under lights?
It would probably depend on the total amount & intensity of light per day.
In Indiana, you would probably give it more hours/intensity of light than they are naturally given in Arizona.