> In the Earth's crust, aluminium is the most abundant metallic element (8.23% by mass[68]) and the third most abundant of all elements (after oxygen and silicon).

TIL. I thought it would be relatively expensive due to the difficulty of extracting it.

(Iron is much cheaper than I thought, too.)

It used to be extremely expensive!

The Washington Monument has an aluminum cap, which at the time was as expensive as silver. Two years later the Hall-Héroult process was invented, and as a result the price plummeted.

Aluminium essentially reflects electricity prices and increasingly recycled