MEXICO, Estados Unidos Mexicanos. 1905-pres. AR Medal (40mm, 33.22 g, 12h). First Interamerican Convention on Mineral Resources, Mexico City. Ciudad de México (Mexico City) mint. Dated 1951. PRIMERA CONVENCION/ INTERAMERICANA/ DE RECURSOS/ MINERALES/ 1951/ CIUDAD DE MEXICO; above, map of Mexico within circle reading INSTITUTION NACIONALES PARA LA INVESTIGACION DE RECURSOS MINERALES / UNA ONZA TROY DE PLATA PURA · LEY 9.925, bust of miner left, wearing helmet with flashlight and holding pick over shoulder. Grove 587a. A few light scratches and faint fingerprints. EF.