I have encased swirls of silvered glass and actual silver which has been heated until miniature galaxies form. I then added a transparent silvered glass for an insane color-shifting effect. This bead varies a lot in colors depending on ambient lighting. The hole diameter is 5mm and will fit most charm bead bracelets.
Pricing and more photos here: http://www.etsy.com/listing/78181155/copperrein-sra-hologram-bhb-charm-bead