Is burned aluminium moka-pot safe to use? The other day, we forgot a Moka Pot on the stove (maybe for 15 or 20 mins) and it got "burned" as in the pics attached.
The Moka pot is made of aluminium, and my modest physics and chemistry background tells me that material-wise, the aluminium hadn't undergone any chemical reaction and should still be safe to use.
Am I correct assuming this? Pictures attached for reference:



 A: I greatly doubt that the pot is zinc. It is most likely cast aluminum, as is every expresso pot like this that I have ever owned. The condition of the outside of the pot does not matter for making expresso or mocha. The inside does not appear to be damaged but if you like there are polishing or cleaning compounds made specially for aluminum cookware that you can buy at kitchen supply stores, with which you can clean the inside of the pot.
A: Tnis answer expands on the answer by Niels Nielsen.
About usage of aluminum in cookware in general:
Aluminum with an untreated surface is very quick to react with oxygen in the air. This forms an oxide layer that seals off the aluminum, preventing further oxydation. This layer dissolves when acidic food is used, so aluminum cookware that isn't surface treated should not be used with acidic food.
There is a process called 'anodizing' that forms a durable oxide layer. Cookware with an anodisation layer like that should not be cleaned with an abrasive.
The natural oxide layer on untreated aluminum is very soft, it rubs off on your fingers.
I concur with Niels Nielsen that that pot is most likely cast aluminum (and no surface treatment).
I take it the bottom part contains water only, to be pushed up by boiling generated pressure. Presumably that is consided chemically safe because only a negligable amount of aluminum will leach into the water.
