title_body: Accidentially put aluminum moka pot on stove without water ... is it still usable?
upvoted_answer: You should be totally fine - and you aren’t the first person who did something like this.
  
  Aluminum melts at a whopping 660C (933K) and while pure aluminum is chemically very reactive, the pot with its oxide layer is quite stable, so whatever you did will have left your Moka way below any temperature range where anything unwelcome may happen. Especially as you report that the rubber gasket is unharmed, and that would be the first part to suffer any heat damage.