The Gemini Ring (3/4" x 1"; Lost Wax; cast in Argentium Sterling Silver, with a matte finish) uniquely features interchangeable, adjustable Velcro* bands for its shank. One size fits all!
The cabochon is an almost-transparent quartz, with a couple of subtle rutiles, so it takes on the color of the Velcro behind it.
This ring comes with all three of the bands in the photo, but I'm willing to add in more (other available colors are blue, orange, and red).
*This is the new generation of Velcro; it does not have the plastic hooks of the original variety. The bands can be worn on either side, but, even though I like the look of the fuzzy side outward, it feels a bit better with the fuzzy side against the skin.