Nicole please do not plug in the cement mixer!
Haha, you made it seem more accessible.... how to get a rock crusher, big investment if we want to make a garden and do not work professionally with it all the time!
Interestingly, as I live in a sloppy place with a lot of rock.... and some of this rock is not basalt, it can be crushed with a catterpillar... and my goal is to make soil with a catterpillar at my place, and crush as much as I can of the soil and mix this with organic matter, which will include burried trunks as low as I can. The thinner on top.
Of course this will not let me with sand-size particles! Unless somebody gives me more practical solutions to do it...
I have the idea I can ask what other machines the guy who will do the catterpillar job has, just in case, because anyway, I know that here in the island, they MAKE SAND! And also mix for concrete. But the machines are HUGE! Also I would make noise and the neighbours will complain, and digging and cruching the soil this way is not authorized, I'd bet!
I think I can do close to an acre.