Because the hub turned on a show about it tonight, and metal is an ongoing interest of mine. And because you probably have aluminum knitting needles and/or crochet hooks. So it's nearly kinda-sorta relevant.
Aluminum is the third most common element on our planet. Unfortunately, it is VERY reactive, likes to combine with other things, and is almost impossible to find in pure form. For that reason, even though it is EVERYWHERE, aluminum was, for many years, more expensive than gold or platinum. No, seriously.
Because of the reactivity, and the rarity of pure aluminum, the history is really weird.
Alum - aluminum mixed with potassium and sulfur - goes way back in our history. It was used medicinally, and as a mordant for dyeing fibers and fabrics. Still is. It's used in pickling, in preserving, all kinds of stuff. But because of all the crazy molecules it likes to form, it wasn't until the 1820s that aluminum was identified as its own little atom.
Not long after, they realized there was aluminum in bauxite:
The Washington Monument is capped with it:
In 1886, the Hall–Héroult process was invented. It pretty much revolutionized industry methods and products. For all people like to go on about steam engines and electricity, without cheap aluminum, the world as we know it today would not exist.
In 1888, the world's first aluminum plant was opened, right here in Pittsburgh. They couldn't refine it fast enough - no matter how much they made, the world wanted more to use. And luckily for us, since it's so common, we've been able to continue refining it with no end in sight.
Not just industry. Limeys? You know this statue?
The Anteros statue in Picadilly Circus was cast from, yes, aluminum. One of the first known statues of its kind, made in 1893. Since we can just refine more, we won't have to melt it down for beer cans, like the Romans did to their statuary.
So, next time you're knitting with aluminum needles? Show them a little respect. And wish it was 1850, so you could sell them and go on a round-the-world tour with the proceeds.