Mineralogy, Geochemistry, and Genesis of Agates from Chihuahua, Northern Mexico

The present study aimed to investigate the genesis and characteristics of some world-famous agate deposits in state Chihuahua, Mexico (Rancho Coyamito, Ojo Laguna, Moctezuma, Huevos del Diablo, Agua Nueva). Geochemical textural studies host rocks showed that all studied are related same rock type within geological unit Rancho el Agate andesite, a quartz-free latite shows clear indications magma mixing. As result their large-scale distribution various differentiation processes, as well transport separation, different textures local chemical differences between localities can be observed. These have also influenced properties SiO2 mineralization rocks. mixing near-surface fluids from alterations with magmatic hydrothermal solutions led accumulation elements matrix agates, which were, on one hand, mobilized during secondary alteration (Fe, U, Ca, K, Al, Si) and, other transported (Zn, Sb, Si, Zr, Cr). Different generations chalcedony indicate multi-stage formation multiple cycles filling cavities fluids. presumably residual rhyolitic volcanism, followed latitic extrusions area probably caused polymetallic ore Chihuahua area. enrichment highly immobile indicates involvement volatile formation. vivid colors agates almost exclusively due mineral inclusions, consist mainly iron compounds.