The latest data on plastics used for imitation amber was obtained by sending a sample to a plastics test lab for FTIR analysis. I previously had found some light yellow "African amber" beads that were made from high impact polystyrene. But many other amber-colored plastic beads I've been accumulating did not test out exactly the same when I used my home-spun methods of reaming or hot needling for odor, or using MEK to check for solvent resistance.

These beads all had a faint odor of styrene so I assumed they were some sort of polymer that included polystyrene. But they were completely resistant to MEK and also did not melt quickly under the hot needle.

I sent a piece of one bead (from the group in the first photo) to the test lab and was surprised to find out that the material was an alkyd resin. Alkyd resins are the materials used for a lot of paints. Chemically, an alkyd is a polyester modified by the addition of fatty acids and other components. This particular one is likely based on castor oil, which helps give the beads a nice luster. Crosslinking agents are added to cure the material into a hard, solvent-resistent bead.

In the second photo, I show other beads with the same characteristics as the alkyd bead that was tested. They are solvent-resistant and hot needles barely penetrate. The dust or smoke odor is faintly like styrene. You can see that the beads have some nice internal swirls and look a LOT like some old Bakelite beads, although the amber color is nice and bright. Also shown are two beads that are definitely polystyrene for comparison.

The closest alkyd resin that the lab had a "fingerprint" for is currently being made only in China - I couldn't find any other sources. So, like many other beads we find today from the African traders, the imitation amber beads made from alkyd resin are most likely made in China.