An element used in labs and games,
A German scientist used his fame.
To name it after the Greeks in past,
A crystallization proved, at last.

Don't throw a fit; it's blue and gray,
I won't forgot the hints today.
It oxidizes with O5 and O2,
That would be your final clue.

Alright, we're starting off with a rather uncommon element. Good luck, guessers :)

~ Rio