Large Dark Blue Agate Necklace and Earring Set. Large square dark blue Agate with small rondelle blue beads and black acrylic pearls between each large bead. Necklace has eight large beads and twenty-one smaller beads and is attached to a chain. Necklace is 18 inches in length with lobster claw clasp and matching earrings. Match up with jeans and you will look like a million.