Divine rulers and ritual specialists in Mesoamerica have long used mirrors, crafted from stony materials like pyrite and obsidian, to foresee what the forces that govern the cosmos hold in store. Mirrors allow for special sight, beyond the limited vision of humankind. In Book 12 of the Florentine Codex, authors describe the seventh omen of the Spanish invasion as the appearance of a crane with a round mirror in the middle of its head. When Moctezuma gazed into its dark surface, he saw the starry sky that hangs over the world-renewing New Fire ceremony, and then an armed horde arriving on horseback.