Yes. Also, fossils will spawn on both kinds of dirt paths, unless that tile is also occupied by a design pattern (for example, I have some stone patterns placed over my dirt paths)
I've got a large sand area I use for my zen garden, and I don't move my rocks around, but I have seen them spawned on sand. I can also confirm that fossils will spawn there as well as glowing spots for your money trees will spawn in the sand area as well.
Edit: Oh and weeds too!
Basically it acts as a normal spot of land, that would have had grass there.. but it acts as sand in the way that it will leave footprints and such there. No shells spawn there either.