Boletín de la Sociedad Geológica Mexicana
On-line version ISSN 1405-3322
PEREZ-SEGURA, Efrén; ESPINOZA-MEDINA, Enrique; MENDOZA-CORDOVA, Abraham and VIDAL-SOLANO, Jesús. Discovery of vivianite in the La Caridad mine, Sonora, Mexico. Bol. Soc. Geol. Mex [online]. 2009, vol.61, n.3, pp. 499-503. ISSN 1405-3322.
The La Caridad mine is located in Sonora and it is the largest mine in Mexico. This is a porphyry type ore deposit dated at 54 Ma. Beautiful green centimetric size crystals of vivianite (Fe3(PO4)2·8H2O) have been discovered at Mercator coordinates 638232 N and 3354816 E, and between benches 1305 and 1410. The identification was confrmed using X ray diffraction and fuorescence. The mineral is in the core of the orebody in the potassic hydrothermal alteration zone, but in the transition from the supergene enrichment to the primary sulfde zone. The origin of the vivianite is probably meteoric, during supergene enrichment. The La Caridad mine is the second locality in Mexico where the presence of vivianite has been reported.
Keywords : vivianite; La Caridad; phosphate; porphyry copper; Sonora.