Curiosity took these photos of sieved sand on sol 1226 (January 17, 2016). On the left is the portion of the sample that passed through a sieve with holes of 150 microns in diameter ("dump pile A"). On the right is the portion that did not pass through that sieve ("dump pile B"). The images have been resized to a scale of 25 microns per pixel; each square image is 10 millimeters across. Apart from the obvious difference in grain size between the two portions, there is also a difference in color, with the finer fraction being redder and the coarse fraction grayer.