We do our best to be accurate in assigning categories. And each bead is a piece of history, with its own story; and organizing our collection by region and time periods is based on recognizing the similarities of certain styles and designs.
But there are always exceptions.

For centuries, Egyptian beads were held to be the finest in the ancient world . Small, easy to transport yet valuable, they became favored cargo of far-ranging Phoenician traders; glass beads were exported all over the ancient world. The relationship of the Egyptian glassmakers with the Phoenician traders was not only profitable, but also the foundation for mutual influence and the Phoenician glassmakers worked with Egyptian technologies to develop a flourishing industry of their own in the centuries at the end of the first Millenium BCE..

For instance, no one can tell an Egyptian eye bead from ca. 500 BC, from a Phoenician eye bead of the same period. They are virtually identical, having come from competing industries; but ALL were traded by the Phoenicians along the routes they covered. So, we generally assign the beads to the category "Phoenician" unless the provenance is expressly Egyptian for a particular item, for example, with the region of origin identified as Alexandrian or as produced in Fustat, an Egyptian glassmaking center.