This strand of interlocking Czech glass beads is called "SNAKE" trade beads because of its similarity to the snake vertebrae. They date back from the early 1900's. These beads have been molded and the strand is in pretty good condition. This black color is very hard! The beads are approximately 10mm in diameter The strand can be worn as is because it is long enough to slip over the head. You can also use these beads as spacers in your own bead creations.