These stones are called Inca Agate. They have a burgundy swirl running down the center with a creamy accent. Like all agates, they are translucent, so you can see other flashes of color as you look deeper into the stone. (Really much better looking in person than a photo can ever do.)
I set these stones using sterling and fine silver and then dangled them from sterling French ear wires.
These earrings are about 1 3/4 inches long from the top of the ear wire.