When I order Czech glass beads or other man made beads I can count on them being the correct size. Most times I use a range between 4mm to 8mm. This is nice because the earrings or both sides of a necklace will be equal in length. But semi precious gemstones can be inaccurate in the size of the bead or even the holes drilled in the bead. So it takes extra time to arrange the beads to get level earrings.
