This is an imitation of a Roman Period face bead, of the type perhaps made at Alexandria around 2,000 years ago. The bead is quite small, and the details are not easy to see, even under magnification. It's a bead I would love to scan at high resolution, so we can see what's really going on. But I suspect it is a fake, and that the details are cleverly painted in and suggested (rather than accurately copied). A scan would most likely reveal all.

JDA.