Nice one, I have seen a few banded slate beads, but not many. Really cool find.
I wonder if it was anciently salvaged from an artifact (bannerstone, gorget, etc.) or if the maker just realized that it was uncommon material and chose to maximize all the material he/she could.
TestingI have seen it used on other artifacts but not on beads. This must have traveled south to BG from Ohio area where this is a more
common material.