Amethyst round semi-precious stone beads. These 8mm gemstone beads are purple in colour and believed to promote intelligence (perfect for exams!). Amethyst is the birthstone for February. These gemstone beads are sold either singularly or strung on a 16 inch/40cm strand of monofilament which contains approximately 50 8mm beads. They are ideal for necklaces and chunky bracelets.