Gemstone Donut Pendants from Rings & Things: Donut beads (or donut pendants) are a large disk with a very large hole. This shape is also known as a ring.
You can turn gemstone donuts into quick pendants using 1mm - 2mm leather or cotton cord, and a simple larks-head knot, and avoid a clasp by making the necklace long enough to slip over the head, or add a clasp to make a shorter necklace. Or capture the donut with a wire-wrap, wire-weave, or seed beaded design.
Odds are, you already know what you want to do ... you're just looking for the right size and stone!