Descubrimiento de vivianita en la mina La Caridad, Sonora, México

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 confirmed using X ray diffraction and fluorescence. 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 sulfide 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.