Berzelius drew his name from Selene, the Greek goddess and personification of the Moon, deliberately pairing his new element with tellurium, which had been named from the Latin Tellus, the Earth. Because selenium so resembled tellurium chemically, he reasoned that if one bore the name of the Earth, its companion should bear the name of the Earth's satellite. The choice sets up a small celestial pairing within the periodic table, Moon beside Earth, and it echoes, without deriving from, the ancient association of silver with the Moon; here the connection is purely one of naming by analogy, a nineteenth-century chemist's poetic tidiness rather than any inherited lunar symbolism.
Before silicon diodes took over in the mid twentieth century, selenium rectifiers were a standard component in radios, battery chargers and industrial electronics, exploiting the same light- and current-sensitive behaviour that made selenium useful in photocells. In glassmaking, small amounts of selenium compounds produce a deep ruby red, prized by art glassmakers as selenium ruby, a striking counterpart to selenium's more common role decolorising glass by cancelling the green tint of iron impurities, the same trick manganese has long performed in the same industry.