I just got Beast Wars II Galvatron off ebay for a good price, and when I get him, I realize he's got an honest-to-god glass marble embedded in his chest! I've never seen glass used in a figure before. He's an awesome figure too, if you don't have him, get one. Anyway, it got me thinking - how many other TFs have glass parts?
I'm pretty sure it's glass. Mine even has little imperfections (dents, lines) that I've never seen in a plastic marble.
I think it's glass or some kind of clear fiberglass. Mine even has the little airbubbles in it. Look at us, playing with Galvatrons marbles.
Yeah, mine is certainly a glass marble. I have some glass marbles of a similar style and size, and they have the same feel, imperfections and all. Though I think this'll be the sole example you're likely to find, in TF anyway.
It could be acrylic. I used to see acrylic cubes with stuff etched into the inside that sat on little stands with lights. I would've sworn they were glass, but found out upon further investigation ( for energon cubes I was gonna make ) that they are not.