Picture is an example, yours will be similar.
Additional information: Prossers are molded beads that are created by pressing a finely powdered dry mixture of clay, feldspar and flint into a mold which is then heated in an oven until the material fuses and forms a glass bead. The technique is named after its inventor, Richard Prosser, who developed the process in Bohemia in the 1830s to produce buttons. Prosser beads can be recognized by the barely visible seam that runs around the center of the outside edge of each bead and by the uniformity of shape and size of beads in a single strand. Initially produced in the Czech Republic, prossers are now made in Morocco using the old Czech equipment.