Professeur Tournesol cobalt unknown alien thing

This is a thing Professeur Tournesol found in his pocket at the end of the 'Flight 714 to Sydney' Tintin comic. He described it as a metal wire ended in an hemispherical head, and said the lab analysis shown it was made of pure state cobalt, alloyed with a ferronickel composite. "As there is no pure cobalt in the Earth, it must have an extraterrestrial origin", he concludes, live on TV.

As the comic images show the thing in the black and white TV set, I don't know the actual color. I was goin