Rose's choice of name was a deliberate piece of mythological wit. Niobium is found together with, and is chemically almost inseparable from, the element tantalum, which had itself been named after Tantalus, the Greek king punished in the underworld. In the myth, Niobe was the daughter of Tantalus, a queen whose boastful pride cost her all her children and who was turned to weeping stone. By naming the sister element after Tantalus's daughter, Rose fixed their close kinship in the language of myth.
The old American name columbium lingered in the United States for over a century, and only in 1949 did niobium become the international standard, though columbium is still occasionally heard in metallurgy. The myth itself is one of Greek tragedy's starkest: Niobe, queen of Thebes, boasted that her fourteen children made her superior to the goddess Leto, who had only two, Apollo and Artemis; the offended twins slew all of Niobe's children before her eyes, and Niobe wept until the gods turned her to stone on Mount Sipylus in Anatolia, where a weathered rock formation is still shown to visitors as her petrified, eternally weeping form. Niobium and tantalum, sharing both a myth and a mineral, are the periodic table's clearest father and daughter pairing drawn from a single family story, a small piece of narrative continuity in a table otherwise built from scattered, unrelated names.