a lot of really vital materials are. And how amazing a thing that is.
The chisels I posted on the other day, for instance. A bunch of years ago I went into an overhead-door company and asked if I could buy some broken springs. They asked why, and the idea of someone forging them into things seemed to make them happy; they took me to a trailer full of them and said "Take what you can use." I grabbed half-a-dozen pieces, all about four feet long. I have no idea how many different things I made out of them; screwdrivers and awls and punches and chisels and flint strikers and small knives and springs and arrowheads.
Think about that. Very good quality spring steel, and they could afford to just give some to me. Historically, it wasn't that long ago that that trailer load would have been a somewhat precious cargo: probably a ton of high-carbon steel of very consistent quality in a form that could easily be used to make any of a range of things, from blades to different springs for instance.
Aluminum. Once so rare there's some in the British Crown Jewels, now so common we can make drink cans and car body parts and electrical wires out of it.
When you think about what was required- in thinking of, in designing, in engineering the ways to better mine and smelt and refine and roll/extrude/stamp these and other metals on this scale... And they're so common people rarely actually think about them.
By the way: few years back I found some small-diameter stone drills- the kind you hit with a hammer- at a salvage place. You want to talk about chisels... I took one piece about eight inches long, chucked it in the drill and used that to spin it against the sanding disk on the belt sander to turn about two inches into a nice taper, then a point; best prick punch I've ever used.