Your bead has been made from a preformed ribbon element, that has been spirally wrapped (from the center, out. So it is something like a variation on a rolled-pad bead. I have documented these occasionally. Not in these colors, however. In addition, it has been combed. (Not "feathered.")

This sort of beadmaking derives from ancient Middle Eastern traditions. It is such a departure from Venetian beadmaking, I have to be very surprised that anyone would suggest this.

Also, the devitrification of the glass suggests it is quite old.

I do not recall seeing a similar bead from the Niger River occupation site digs. But it might be that. There are certainly rolled-pad beads and combed beads among the Mali beads.

[Ten minutes later]. I just looked through Panini's great book on ancient (and Venetian) beads from Mali/West Africa (2007)—to see if there are any similar beads. There are not. I even went through the Venetian/European pages. Same result.

Conclusion: I think you have an ancient bead here, of spiral manufacture, with a combed equatorial band. It's not a Venetian bead, nor a modern European bead. It might be an odd bead recovered in Mali—but it is also a departure from those beads. Jamey