It's strange how beautiful a block of stone can be. Four works of art made of rock and shadow: ( from
http://www.lyle.org/mars/ )
Sol 78: Boulder in the Bonneville ejecta blanket.

Sol 99: Flat boulder between Bonneville and Missoula covered in sand drifts.

Sol 128: Similar rock, but better shadows.

Sol 168: Two eroded rocks at the base of the Columbia Hills.