The rock "Ithaca" shown here, with a rougher lower texture and smoother texture on top, appears to be a piece of the local sedimentary bedrock protruding from the surrounding soil in Gale Crater. NASA's Curiosity Mars rover used its Mast Camera (Mastcam) to take this image during the 439th Martian day, or sol, of Curiosity's work on Mars (October 30, 2013). The black-outline rectangle indicates the area where the rover's Chemistry and Camera instrument (ChemCam) used its laser and remote micro-imager to inspect Ithaca. That inspection included the 100,000th laser shot fired by ChemCam on Mars. The 0.1 meter scale bar at lower left is about 4 inches.
Photo credit: NASA/JPL-Caltech/MSSS
Note: For more information, see PIA17591: Target for 100,000th Laser Shot by Curiosity on Mars, PIA17593: ChemCam Spectrum from Martian Rock Target 'Ithaca', and Laser Instrument on NASA Mars Rover Tops 100,000 Zaps.