the three darker ones are 68 mm diameter and 34 and 40mm thickness, I think too it's bakelite. The light ones seem to be a resin, the texture is very different and are 57mm length, 53mm wide and 23mm thick. I tried the hot needle test: on the resin, the needle puts out the resin, but it's hard to smell something. There is a picture of another beads which seem to be bakelite too: please, look at the big bead left after the two smaller and the bead right after the small one, they are lighter than the darker ones and thicker too: 45 and 51mm, and 57mm diameter. There are two beads like this, one on left, one one right.
The last pic shows a necklace of faux amber which seems colored horn.