pyrolusite, which was my assumption up until that point. If I recall, it's compositionally equivalent to that mineral, but amorphous. While quite apparent at the above scale, the variety of forms is best appreciated in the full-size version of the photo (right click and select "open link in new tab").
Photo unmodified. August 19, 2011. FlashEarth Location.
Is This Your Hat?
2 years ago