Why not link to the NASA page directly? I really don't see how the blog adds anything. Here it is with some high quality images: <a href="http://www.nasa.gov/jpl/mer/rock-pinnacle-island-pia17761/index.html#.Ut_JsmQ1i2w" rel="nofollow">http://www.nasa.gov/jpl/mer/rock-pinnacle-island-pia17761/in...</a>
There are two small very straight lines on the lower right of the object that hints that it's man-made. Really looks like something just fell off of the rover, rather than was knocked there from the ground nearby. There's almost no disturbance of anything else in that area which would be expected if that object rolled or was pushed there. Looks like it fell down on top.