Spindle whorls were used as weights as part of the textile tool, known as the spindle. These beads, typically made from ceramics, stone, shale, wood and animal bones, were used to help give the spindle momentum in the twisting or spinning of fibres into yarn. This yarn would later be used to create textiles. Roman spindle whorls were typically made from reused glass which meant that the spiral pattern came from the glass being remoulded into the smaller bead. The spindle and other textile work was something which was strongly associated with Roman women. The hobby of loom work was something which many high-born Roman ladies practiced, the spindle would have been involved in the feminine tradition of creating clothes or tapestries.
For more information on Roman glass please check out our blog post: Collecting Guide: Ancient Roman Glass