Shining, silvery mercury, or quicksilver, is the only metal that is liquid at room temperature. The rather rare element is usually obtained from cinnabar or cinnabarite (mercury[II] sulfide, HgS). Viable mineral deposits are few: the mine at Almadén in the Spanish region of Ciudad Real alone supplied almost half of all the mercury ever mined, followed by that at Idria in the former Habsburg Carniola (now Idrija, Slovenia), which provided around 13% from 1493. The largest German reserve, at Obermoschel in the Rhenish Palatinate, was far less significant.

Alloyed with other met…