A bead is a small, decorative object of various shapes & sizes, being solid or hollow, but usually pierced for threading or stringing. Beads range in size from under 1 millimetre to over 1 centimetre in diameter. A pair of beads made from Nassarius sea snail shells, approximately 100,000 years old, are thought to be the earliest known examples of jewellery. Beadwork is the art or craft of making things with beads.