They're actually pieces of the dome; it's a long grain Damascus type of manufactured nickel-iron steel alloy with a gloden oxide.
Why is the dome falling apart?
Well, why you have to ask those questions, come on... If notbatman says it's made of ''bla bla'' and it's falling, it is. Notbatman should build a rocket and crash it into the dome, easy proof.
Oh yeah... so maybe it's all those fake NASA rockets going up and crashing into the dome and making chunks of it fall down?
Come on, notbatty, we're helping you out here with the excuses. Quit slacking off, entertain us.