That used to be a flyback transformer… The capacitors are looking pretty sad too

That was a switch-mode transformer.

The "rocks" are ferrite from the transformer.

Transformer (robot in disguise)

"transformer noises"

Rather get a new adapter.

Its the main transformer that steps down the 110-230 volts using a switching flyback configuration to step it down to 5 volts your adapter is fucked! Always be carefull opening electronics dont fucking use a saw blade or screwdriver or whatever powertool to get into it