Yttrium is a rare earth metal,
crystaline and structural.
First found in Sweden in Ytterby,
that much for etymology.

From Carl Axel Arrhenius,
an ore, non-homogeneous.
Seven different elements contained,
with big difficulties gained.

Wöhler reduced Yttriumchloride,
to a metal silver-white.
Which can easily burn and oxidize,
using it as a ceramic is very wise.

Or as addition and enhancement,
there Yttrium is prominent.
It is a grain size finer for many candidates,
Molybdenum, Chromium, Zirconium in metal states.

In Zirconia the cubic phase stabilized,
YSZ and its properties, you would be surprised.
A high tech ceramic application,
a clever variation.

Furthermore it is used in L.A.S.E.R and magnets,
very special ones in superconductive states.
Combined with Barium and Copper,
working with liquid nitrogen proper.

It can be as well a semiconductor as nitride,
pure or strongly modified.
Yttrium is a high tech variator,
a stabilizer and modification creator.

Light state, energy levels, grain size,
knows where to emphasize.
A rare earth indeed,
but here and there the change we need.