Though I am not at home and are therefore with no access to photos and literature, I wonder why none of the beads discussed here are on display in the Warmensteinach museum? At least not, when I visited in 1992 and the early 2000 years. Maybe that has changed? Were any of those on display recently?

Another thing I wonder about is the bead release being used for the furnace wound beads from the North-Eastern Bavarian Fichtelmountains discussed here. To my knowledge a sludge with a high content of a porcelain-ceramic (some kaolin/quartz mixture) was used for beadmaking in the Fichtelmountains (not FICHTEMOUNTAINS, as Rosanna wrote).

Since I am not certain how the risidue of such a "Fichtelmountain-Sludge" looks like some 100+ years after the bead was made, we should find out - or compare - into what color an obviously whitish-beige sludge turns after firing century-long use. That would certainly be cheaper than a chemical analysis of the glass.

There is no question that Fichtelmountain beadmakers made the glass-rings we all know any possibly own (in various colors from transparent, amber, green, red and a darker blue in most cases). But again: None of them visible in the local museum. They had glassrings on display (during my two visits), but none of the known colors nor in the rather perfect conditions we usually see from the African trade.

I am NOT (!) saying Bavarian bead makers did not make either beads. I just state what I have (not) seen in their little museum (in 1992 and around 2005).

What I am saying though, is that local beadmakers used a specific ceramic/porcelain/kaolin kind of beadrelease "sludge". The whole area is well known for their high-quality production of porcelain items (Selb and other).

PS
Another, (most likely) unrelated fact is that Bavarian beadmakers had obviously early relations to (bead-, or glassmakers) Venice and also Bohemia.

PPS
"FB beads" - as Rosanne and/or proposed - is not a good abbrevation for (this) beads from the FICHTELMOUNTAINS, I think. What should the "B" stand for? If an abbrevations is needed at all (maybe for the communication between collectors) and if it were confirmed the beads are (only) from Bavaria, the abbrevation "FM" for FICHTEL and MOUNTAINS would be the better choice, in my opinion. Maybe I misunderstood something here?