The grains are angular but not always cubic. Photo by Spilde, Northup, and Boston. SEM closeup of the preceding image. Photo by Spilde, Northup, and Boston. Photo by Spilde, Northup, and Boston.
Image shows a pitted area with some iron specks on top.
Photo by Spilde, Northup, and Boston. Some evidence of corrosion pits. Photo by Spilde, Northup, and Boston. The size and collapsed look suggest that these could be bacteria. Photo by Spilde, Northup, and Boston.