The photos above come from Beki's Haley's Out on a Whim website. The originals (click the photos) are larger and show the sharp facets on crystals compared to so-called "fire polished" glass beads.I've always wondered where the term "fire polished" came from. Lots of times, vendors create exotic nomenclature to spice up a less than stellar bead or gemstone. But Czech fire polished beads are first quality -- so, what's with the name?
A couple of expert vendor/collectors solved the mystery for me recently. Apparently the FP beads are pressed glass, and come out of the molds with bits of flashing on their edges that need to be tumbled off. The tumbling dulls the glass surface, so they're heated over fire to restore their shine.
Chris says, "A Czech bead seller acquaintance informed me once upon a time that it takes a couple of years - yes, years - of training to develop the judgment necessary to tell when to pull the trays of firepolished out of the oven."
The polishing softens the edges, making FP beads distinguishable from lead glass crystal beads, whose edges are much sharper (again, check out the photos at Beki's site).
Contrary to what I've heard over the years, the lead content in the crystals doesn't actually make them more durable -- nor does it make the edges sharper. The lead content does, however, make the faceted beads more reflective.
Chris shared this link: http://www.lenntech.com/Glass.htm for a quick summary of glass types and what they're good for.
Many thanks to these bead-pros for sharing their knowledge about fire polished beads:
Beki Haley is a jewelry designer, metal clay and beadwork instructor, and owner of the bead store Out on a Whim in Cotati, CA (and on the web).
Chris Prussing is a bead collector and was a long-time bead shop owner in Juneau, AK. She is the author of Beading with Right Angle Weave and temptress of BeadHell, where this discussion originated. Recently, Chris opened up an Etsy shop to sell her beaded kits and creations.