Scanning electron microscopy (SEM) images revealed mainly the formation of highly symmetrical particles having a double-decker flower-like morphology (Cu-AdDB; Figure ). These unusual structures have two pairs of six symmetrical petals with hexagonal convex stigmas. We also observed that some of these particles have a hexagonal core and that the six lateral faces of the core form the bases of the petals. A gap exists between petals of opposite decks. The two decks of the individual particles display strikingly high similarity, both in size, shape, and alignment. Analysis of 50 structures revealed a size distribution of 35 ± 6 µm and ~5 µm measured from the diagonal and opposite apexes, respectively.