If you've held a Euro banknote, then you've held europium.
Named after the Western continent, europium (atomic no. 63) is luminescent. For that reason, it's used in Euro banknotes as an anticounterfeiting phosphors. Under certain conditions, the banknote will appear red. Europium is also used in LED screens in TVs for red coloring.
For the Monitor, science reporter Pete Spotts reports: "Europium, for instance, helped drive the shift from black-and-white to color TV by turning the dull reds in early TV screens to reds that popped. Erbium placed at intervals along fiber-optic lines amplifies the light carrying data, allowing it to travel long distances."
