I've always loved crystal. Something about it being clear, but refracting the light into rainbows thrills me.
This particular bead isn't actually clear. It has what is called an aurora borealis coating on it, making it more rainbowy.
But that iridescence just is way too cool for me.
The beads in the chain also have the ab coating, but they don't show as well in this picture.
Sometimes I worry that my tastes aren't sufficiently sophisticated, but then I am reminded that diamonds also are clear and refract the light in much the same way. But without needing any coating.