As I understand it, they aren't really like a solid web of graphite or carbon fiber as you'd see in bike or airplane parts, but instead are some composite, maybe Delrin, with loose graphite fibers in the blend. So yeah, they're kind of a light weight plastic-ish pick with enough carbon fibers in there to put some grit in the surface. That tiny bit of grit is part of the magic that plastic picks simply don't have. It's like a warm, fat, darkish pick, but with a clear, upper harmonic "zing" that the gritty surface excites in the strings. You can take a Dunlop plastic pick of the exact same dimensions and it'll sound very different. They're special picks in their own right for sure, not just because Jerry and Trey chose them.
B
... and it's just like any other day that's ever been...