Polyester resins are often modified with fatty acids to make compounds called alkyd resins. I had a Bead that looks like these tested at a polymer lab and it was ID’d as alkyd. The material is cross linked so it won’t melt and is very resistant to solvents.

Somehow, the technical term for fatty acids might wind up being translated as chicken fat or another lay term. Just my suspicion based on playing with a number of new plastic amber imitations. They are quite attractive, in a kind of plastic-y sort of way.

I’m traveling right now so I can’t post the pix of the alkyd Bead I had tested. But it was purchased from a Tibetan bead seller about 18 months ago.