In 1792, a chemist named Gadolin received a sample of a mysterious black rock
from this now-closed Swedish mine.
It was far too heavy to be coal:
it was called ytterbite, after Ytterby, the nearby town.
Nowadays, we understand the basics of chemistry.
We've named all the natural elements and we've made our own.
But back then, it wasn't just that there were gaps in the periodic table,
it's that there wasn't a periodic table at all.
Heck, when Gadolin was given the rock from this mine,
Lavoisier, known as the father of chemistry,
had only just published the paper setting forward the theory of elements:
and even he speculated that those elements might include light and "caloric",
an invisible fluid that explained how heat worked.
It was plausible at the time.
The way to work out whether something was a new element was basically:
do stuff to it and see what happened.
Which is still the technique today,
it's just that "do stuff to it" is now defined as
"smash atoms together in a particle accelerator
and track the bits of radiation given out as the results decay".
For centuries, though, it was things like
"heat stuff up and see what wavelengths of light come out"
or "put different voltages of electricity through it and see how the current changes".
The big problem was that the samples that those chemists were working with
weren't anything close to pure,
and they couldn't know how to purify something
that hadn't been discovered yet.
So they had to work out:
was that a new element that they were looking at,
or just a combination of known ones?
So papers were published that turned out later to be completely wrong,
and were corrected by others: which is great, because that's how science works,
but it also means that a lot of people and places
that might have had elements named after them were disappointed.
Canada, Norway, Russia, unlucky.
Ah, there were discoveries to be made.
Through the 19th century, Gadolin and other chemists
found that the black rocks from this mine had not one,
but four new elements that were completely unknown to science.
And they were all named after here: yttrium, terbium, erbium, and ytterbium,
making this small town in Sweden
the only place in the world with four elements named after it.