This working so far. I dug this large sandstone slab up a few years ago. It's more or less 5 1/2 - 6" deep and 18" x 29", so it's not something I move around much. It had natural holes? or depressions and water apparently drains since it disappears faster than evaporation can account for. Either it has cracks I can't see or the sandstone is just absorbent enough to pull in water - maybe both since you can see cracks going to a couple of the depression. Anyway, I decided to try and see if some semp rosettes would grow. They've been there a while and seem firmly in place now. They all came from a semp I bought as 'Purple Beauty', so I don't know why one rosette is green and the others aren't. It makes me want to see if I can chisel into a smaller sandstone and make a container.
