Europium is sort silver metal. It was discovered in Paris (hence the name) by Eugene – Anatole Demarcay in 1901. It is found in the rare earth metals or the Lanthanides.
Strangely, it is found in moon rock, in much higher amounts than expected. Moon rock also contains to 2+ ion, rather than the 3+ ion found on the Earth.
This implies that the Moon was formed under reducing conditions and also, perhaps more importantly, that the Moon and Earth are made from different sources.