

It’d be coated, but it’s from processing, cold rolling metal generates a lot of heat, especially going that thin (thinnest I was around often was ~0.2mm), we’d often temper the material after processing, mainly for surface finish, mill rolls would be sprayed with lubricating coolant really close to what you’d see in use on a milling machine. This was with steel but same principle applies, pretty sure the lubricant we used is also labeled for use on aluminum mills, but you’d use food safe stuff for kitchen foil.
Same vein, the Canadian/Laurentian Shield has areas dating back as far as 4.2 billion years, recall a geo prof in uni suggesting it would have been extremely tall, Wikipedia suggests 12km.
Stuff gets unreal to me at geological timescales.