If it doesn't reflect light, it'd be black. If it emitted its own light then there wouldn't be shadows in the craters of the moon and we also wouldn't have moon phases. It's hard to tell if this person is actually being serious because this is literally just entry level physics. Plus, we've collected moon rocks during the numerous moon landings.

Everybody wants a rock…

I used to canoe on this lake in Wales, someone had attached a buoy to a gate and chucked it in, presumably as a marker…from where our camp was, the buoy looked shiny and metallic. It was actually white and partly covered in grime. Distance does weird shit.

If rocks emit their own light, how come you can land on them?

If you can see it, it's reflecting light