A couple of days ago I've discovered that one of the hallii has regenerated into a variegated specimen. I've read about this phenomenon and in lithops it is something that stays for a year and goes away with the next leaf change (even though there are exceptions). It looks interesting.
Speaking of hallii, there is a new tenant on the windowsill. As if I could visit a nursery without buying at least one lithops, and such a nice one. :)