A fine 18th c, possibly late 17th c, Spanish Colonial era silver tupu (or tupus).  These were pins used by Andean women to secure their cloaks or other garments, and based on the quality and level of adornment on this example, this was probably owned by an aristocratic woman.  It was crafted in Peru, and they had often incorporated Inca motifs into the designs.  The double-headed eagle, however, harkens to Europe's Hapsburg Dynasty.   It measures approximately 11.5" long.