Erbium is a lanthanoide,
a metal forming a pink oxide.
Locally concentrated and rare,
Erbium is not anywhere.

Therefore the prove of existance,
was not made in an instance.
In company of Yttria there was Erbium,
but as well there was Terbium.

As similar the names might be,
there was discussion scientificaly.
Mosander knew of both, but others not,
the existance of both was disucussed hot.

In the end Erbium got confirmed,
and the honour was rightously earned.
Erbium metal was first confirmed a century later,
from erbiumchloride and potassium vapour.

A very dangerous reaction by the way,
nothing to repeat for fun i need to say.
Bommer and Klemm found it silvery white,
a metal that as powder does easily ignite.

The main usecase of Erbium is in L.A.S.E.R application,
typically a YAG- Laser variation.
This is used in human medicine for surgery,
or in dental cleaning to be bacteria free.

To colour ceramics it is used Erbiums pink oxide,
or as well pink the Erbium chloride.
Together with nickel it forms an excellent cryo coolant,
the Erbium leads to an excessive heat capacity improvement.

A special element just explicetly used,
and scientists have been confused.
Over a pink oxide former now part of modern medicine,
to cut and make your teeth clean.

I love the fact that a small amount can make the difference,
that it can alter, improve and enhance,
it is up to us, if we are the Erbium in our neighbourhood,
active, beautiful, positive but never clearly understood.