Tantalum

Tantalum was discovered in 1802 by the Swedish chemist Anders Gustaf Ekeberg, in minerals from Scandinavia. He named it after Tantalus of Greek myth. For decades it was confused with niobium, which occurs alongside it, until the two were finally distinguished in the 1840s and 1860s. Tantalum is a hard, blue-grey, extremely corrosion-resistant metal, biologically inert and so used in surgical implants, and above all in the tiny high-capacity capacitors of mobile phones and computers. Biologically inert and highly resistant to corrosion, tantalum is used in surgical implants and instruments and in chemical-plant equipment that must withstand hot acids, as well as in the compact capacitors that store charge throughout modern electronics.

Tantalum has become one of the most closely watched conflict minerals of the smartphone era: much of the world's supply is drawn from coltan, a tantalum-niobium ore mined in the eastern Democratic Republic of Congo, where revenue from artisanal mines has at times funded armed militias, prompting the tantalum-specific due-diligence and disclosure requirements written into the United States' 2010 Dodd-Frank Act and similar European Union regulation aimed at tracing the metal's supply chain back to its source.

Ekeberg's name is a piece of mythological wit grounded in a chemical observation. Tantalus, a king of Greek legend, offended the gods and was condemned in the underworld to stand forever in a pool of water beneath a fruit-laden branch, yet whenever he stooped to drink the water receded and whenever he reached for the fruit the branch drew away, so that he was eternally tantalised, the source of the very word. Ekeberg found that the oxide of his new element, immersed in acid, would not take it up or dissolve, standing amid the acid as unable to drink as Tantalus himself. The kinship deepened when niobium, the sister element found with it, was named after Niobe, the daughter of Tantalus, fixing father and daughter side by side in the periodic table.

Accounts of Tantalus's original crime vary across ancient sources: some say he stole ambrosia and nectar from the gods' own table to share with mortals, others that he killed his son Pelops and served the boy's flesh to the gods to test their omniscience, a horror the gods detected and punished by restoring Pelops to life; either version casts Tantalus as a mortal who presumed too far on divine hospitality, a fitting frame for an element whose oxide likewise refuses to yield to the acid pressed upon it.