Walter Jeffries is using basalt rebar in his butcher shop, which progresses apace. For some reason that blows my mind, I'm not sure why. Maybe because I think of basalt as a rock, a solid, not as something which once was liquid and could be liquidified again.
See the site here. I note the local supermarket has stanchions (upside down U's) to keep their carts nearby, and some of the stanchions have rusted where it goes into the concrete.