Vermiculite is terrific for recreating coarse dirt or “aging” a set.
And if you want to create the look and feel of quicksand, spread vermiculite on top of water. Effects Operators and Art Directors have been using this recipe for quicksand for decades.
In the movie Alien, Ridley Scott used vermiculite as flying debris—he even mentions it in the director’s commentary. Scott calls vermiculite “plastic”—but that’s wrong!
Vermiculite is a very lightweight MINERAL (sometimes referred to as CLAY).
CAUTION: This product does create respirable dust. Wear appropriate protective equipment.