The Museum of Arts & Design (at 2 Columbus Circle) has a cool exhibit on now. "Swept Away: Dust, Ashes, and Dirt in Contemporary Art and Design," up through August 12, focuses on works made out of unorthodox materials -- a murder of crows out of burned wood, say, or designs "printed" with smog on porcelain that was blocked with a stencil and left exposed to the ambient haze of LA for months.
Above left, a sand painting by Joe Mangrum, who I believe mentioned he was installing another such painting encircling the MAD building in Manhattan on June 8 and 9; above right, a smog piece by Kim Abeles.