Rock on On!

A truck has just come by and dumped all this lava rock on my friend's driveway. They are going to put it around the house (like some sort of DMZ to keep the horde of encroaching weeds at bay). I asked the driver where do they get this stuff, anyhow? He didn't know.
Is there a volcanic island somewhere in the South Pacific where the locals mine their igneous rock and ship it to lawn centers around the world? And if so, aren't they chipping away at the very foundation of their society? (although, I suppose, lava is a
renewable resource, but only if your local volcano is active) It all seems slightly dodgy to me. Here we are talking about Third World debt relief, while we should be talking about sustainable lava rock removal. How many islands need to disappear in an orgy of self-destructive capitalism, before we step-in and do something about it? Now I'm looking at this lava rock like some sort of blood stone...
Yeah, well anyways, it is pretty light, so it shouldn't be too much of a hassle to shovel it off the driveway and onto a more convenient spot. I like to think that somewhere on Tonga right now a home owner has just gotten a delivery of crushed New England granite to put around the outside of their home (you know, to hide all that ugly red volcanic rock...).