Most modern imitations of amber are made from thermosetting phenolic plastic that was developed in 1926 (in the US). Beads of this material, from any context, must postdate this year. The thermolabile or thermoplastic beads are harder to date, because this TYPE of material is older. However, most of the beads we see are most likely 20th C. products.

I would estimate that thermosetting (phenolic) plastic imitations outnumber thermoplastic imitations by at least three or four to one. That is conservatively speaking. The phenolic percentage may be (or may have been) even higher.

Nevertheless, I am writing about the beads I have documented since 1972, that were presumed to be (and most likely were) "older" plastic imitations of amber from Africa. In recent years (in the past ten years particularly), amber fakes have been coming out of China, that clearly were intended to copy older African fakes—and many of these are thermoplastics. So the statistics are now different from what they were in the recent past. I can't estimate how much new Chinese plastic has been taken to Africa, and insinuated into the beads of local people. It may be a considerable quantity.

Jamey