Around the vast Indian Ocean, peoples spoke different languages, ate different foods, and worshiped different gods. But they shared a love of glass beads, which typically were strung together to make colorful bracelets and necklaces. Enormous effort and skill went into making huge numbers of baubles as small as 3 millimeters in diameter in a dazzling array of colors.Ancient cultures made glass according to characteristic local recipes. So modern-day archaeologists such as Laure Dussubieux can use these colorful bits of glass to trace movement around the Indian Ocean. Many researchers show up regularly at Dussubieux's lab in the Field Museum in Chicago, Illinois, with their beads from their own archaeological sites, hoping to trace trade routes across the ancient Indian Ocean.