Beautiful Wire Jewelry for Beaders: Creative Wirework Projects for All Levels by Irena Miech. It is made with 16g silver wire for the ring shank and a smoky quartz focal bead that is attached with 24g wire. The book gives the basic technique, but I found the measurement information confusing, so I just winged it.
Making the Swirls
The hardest part of making the ring shank was getting the 'swirl' on either side even. I found that it took about 1 inch of wire to make the swirl. I worked the shank flat and made it nice and even, then curved it around the ring mandrel at the appropriate size.
Making the Ring the Right Size
I made several of these - varying the materials and design slightly with each one. I wish I hadn't sold them so quick or I could post pictures of the other variations. I made one with gold and turquoise that I gave to a friend, so I'll try to take pictures of that one.