This is a type of glass bead known as Nueva Cadiz. It is named after a 16th-century Spanish colony in Venezuela where this type of bead was first recognized. Hundreds of Nueva Cadiz beads have been excavated from the fort thus far. This bead was probably purchased in Venice as part of the colonists' trade kit. Its blue color would have been particularly attractive to the Indian chief Powhatan as he is said to have preferred beads the color of the sky.