from Enclyclopedia Brittanica: "Lucite, also called Plexiglas, British Perspex, is a trademark name of polymethyl methacrylate, a synthetic organic compound of high molecular weight made by the combination of many simple molecules of the ester methyl methacrylate (monomer) into long chains (polymer); this process (polymerization) may be effected by light or heat, although chemical catalysts are usually employed in manufacture of the commercial product."
Okay, so that is great for scientists, but how about the rest of us . . . I asked a veteran plastic seller on Etsy, Age Of Plastic https://www.etsy.com/shop/AgeofPlastic, for some advice. Here is her response:
"Lucite
can be molded or carved. It can also have seams, although I don't know
how common that is (I think I've owned one Lucite bangle with a seam).
On your better Lucite pieces, even if they were molded, they will have
been polished to remove any sign of mold marks. Generally speaking,
collectors and sellers consider the presence/absence of mold marks and
seams to be an indicator of quality, and occasionally to exclude a
plastic when identifying. In some types of pieces, like Japanese
celluloid floral bangles, seams are expected because of how they were
constructed and have no bearing on their value."I also found out that although clear in its original state, Lucite can be tinted virtually any color, in ranges from transparent to opaque, with a few interesting variations along the way.
Now, how can you tell what the plastic is? The best test is to run the piece under hot tap water, or wear the bangle while you relax in the hot tub or shower. If it smells a little like your old high school chemistry lab (formaldehyde), it's Bakelite. If it smells like Vicks Vapo-rub (camphor), it's Celluloid. If it smells like burnt milk, it's Galalith (1920's). If it smells clean, or like nothing at all, it's Lucite or acrylic.
