Nueva Cadiz and associated beads are among the earliest categories of European glass beads found in the Americas. Named after the site in Venezuela where they were first identified, these tubular, square-sectioned beads occur in regions of 16th-century Spanish colonial trade. A similar style occurs around Lake Ontario in northeastern North America in areas of 17th-century Dutch and French colonial trade. We compare the chemical composition of beads from South America and Ontario, Canada, to explore their provenience and technology. Differences in key trace elements (Hf, Zr, Nd) strongly indicate separate sand origins for the two bead groups. Comparison with soda-lime glass made in Venice and Antwerp reveals chemical similarities between the South American beads and Venetian glass, and between the Ontario beads and Antwerp glass. The analysis also sheds light on beadmaking technologies.