Here is link to a discussion about what is going on in the amber market, from just last year. Some of the beads look just like yours. In this thread there is a link to a post by Red, that is very interesting (and disturbing) as it talks to the problem of identifying some beads that are being sold as amber, but are not natural Baltic amber, but may be some sort of plastic resin / amber concoction.

The Search feature of this forum may get you some other interesting material to study. Note that when using Search, you enter the older date first, then the more current date. An example would be, "search from 400 days ago to 30 days ago".