|Stockholm—Carl Gustaf Mosander elements|
Mosander found two impurities, both oxides, in his oxide of yttrium—one yellow and the other rose. Having named yttrium from the first syllable of the village where it was found, Ytterby, and the second after the second syllable, he named the third after the trailing letters, erb. Mosander named the rose oxide terbia, and the yellow oxide erbia, but Berlin named terbia erbia, so Marc Delafontaine named erbia terbia.
Atomic number 68
Erbium doping is used in amplifier-lasers for fiber optics and long-distance transmission. Erbium-doped yttrium aluminium garnet lasers are useful in surgery and in dentistry. Erbium oxide’s pink color makes it useful in glass, glazes, porcelain, and cheap jewellery. Erbium improves the workability and increases the softness of vanadium alloys.
Tweedledee and Tweedledum
They stick together, with similar desires, similar fears. Instead of poking fun at them, let’s respect them as equals. Our imaginary friends don’t laugh at themselves.