This bead had a rather large chip out of it so I had it repaired by a shop that does restorations on antique items.

The repair matches the white trailing and black background quite well, but the base material (likely an epoxy resin) has turned green-ish on the end, in the 3-4 years since the repair was done.

So it is now obvious that the bead has been repaired & I'm not sure it was worth the money spent on it.