Soft sand in Hidden Valley, caught with the MAHLI.
NASA description: NASA’s Mars rover Curiosity acquired this image using its Mars Hand Lens Imager (MAHLI), located on the turret at the end of the rover’s robotic arm, on August 6, 2014, Sol 711 of the Mars Science Laboratory Mission, at 15:35:12 UTC.
Sol 711 raw images (from all cameras), and Curiosity’s latest location map.