Published online by Cambridge University Press: 20 January 2017
A corroded white-metal lip plug from Guerrero was shown by wet-chemical and spectrographic analyses to have originally contained over 99% lead. After reviewing 16th-century eyewitness accounts, linguistic evidence, the mineral resources of Mexico, the technological problems involved in the primitive extraction of lead from its most common ore, galena (PbS), and the few early lead artifacts reported from Mexico, the authors state their opinion that the smelting of lead ore and use of metallic lead were known before the arrival of the Spaniards and that there is no valid reason to doubt that this object was made before the Conquest.