A mirrored doublet of the array from HiRISE image ESP_016032_2600. This shows the probable full count of 12 petals in the full circular shape, seen as a half circle with 6-7 exposed petals in the unaltered original enlarged image.
The counting of the seventh petal only once, due to the alignment of that petal with the diagonal across the circle outline gives a count of 12 total. This is a natural symmetry formation count, and gives me some confidence that the array is either complete but covered in the upper half by a viewable dark layer of material, or that the array is partial, and given to a restriction in the arrangement only allowing half the total count. As one petal is partly on the burial line, and seems fainter but well formed, I have confidence in the regular measure between petals. Other views of this item are found in this Twitpic list, and in my Imageshack.us account in the name ' danajohnson0 ', as below.