The owner had tried to ID it by burning and sanding off various spots on the surface, making it look rather gnarly. The untouched beads had smoother surfaces and a uniform color. This is the bead he sent me though. I fractured it and observed the pale fibrous structure of horn in the interior. Hot pin tests gave the typical burning keratin odor.
The owner had a large strand of these and so could spare one.
I’ve seen other horn beads mis-repped as phenolic resin, and have bought some so I could examine them, so this bead didn’t surprise me. Some horn beads are very nice and shaped like old phenolic beads. I’ll show some photos tomorrow.