Fantastic Orange and Black 18mm Bumble Bee Agate BeadsPrice is for 15. 5 inches of these knotted beads. There are 20 beads in a string each beads measures 18mm ,hole size is 1mm. Agate is one of the most common bead beaders use because it is readily available in an abundance of styles and shapes. What is agate? Agate is a variety of microcrystalline quartz that forms in layers and many colours and texture, by filling a cavity in a host rock although it is usually in round nodules with bands looking like