Gallium

Gallium is a silvery metal that melts at about 30 °C, so a piece will turn liquid in a warm palm. Dmitri Mendeleev predicted it in 1871, and Paul-Émile Lecoq de Boisbaudran found it four years later, naming it after France. It is not mined on its own but recovered in small amounts while refining aluminum ore, and today China produces almost all of it.

Nearly all gallium ends up in semiconductors. Combined with nitrogen as gallium nitride, it makes the blue light of every LED chip in the backlight. Combined with arsenic as gallium arsenide, it makes the infrared LED in the remote control.