Uses for 15 yards of lava rock.

I have the opportunity to get 15 yards of red, landscapring-style lava rock (mafic foamed basalt) delivered free.

So far, i've come up with a few potential uses:

-Soil additive to help aeration
-Soil additive for minerals (iron, magnesium)
-Aggregate in concrete?
-Some kind of insulation? (it is porous)
-Mulch (it doesn't have to be completely weed-free)

Can anyone think of some other uses? Or clever ways to apply the ideas above? I'm thinking about getting it but I'm curious what other ways i could put it to use.

I'm on a flat 2 acres with a roughly 50 by 70 pond. Often wet with a high water table and occasional flooding (every 3-5 years). Zone 5/6 MI, pretty cold. Low elevation.

Hey Matt. Not exactly an answer, but perhaps relevant - my landlord dumped a mountain of basaltic reds behind our apartment building years ago and.... forgot about them, and since they refuse to let me alter the yard, there they have stayed. However, I take them for use in the garden (elsewhere), and noticed after a winter of sitting cozy, they almost totally disintegrated in the middle, and I couldn't find a handful that wasn't mostly comprised of earthworms. It was only the bottom/middle of the pile that had decayed into some tasty vermiculture, but I thought it was cool.

Wouldn't have guessed pumice becomes worm food that easily, but its clear they love the crap out of something in that pile....