Show ORES OF THE YOQUIVO DISTRICT MEXICO owing to its isolation and comparatively small tonnage the yoquivo mining district in the state of chihuahua mexico is is not widely known though financially important and geologically quite interesting stated C W hall of trenton irenton new jersey in an address made at the recent meeting of the american institute of mining and metal surgical lurg ical I engineers in new york yoquivo is essentially a silver gold district silver has constituted about three fourths and gold one fourth of the output total production to 1908 when the present owners the yoquivo development company entered the field is not recorded but from calculations based on the area of the old workings it is estimated production before 1908 about equals that since from inception of operations by the above named company the total ore extracted has amounted to above tons assaying gold oz and silver oz or a total of oz silver and oz gold products shipped have aggregated tons of high grade ore tons of concentrate and 68 tons of bullion the shipping ore has averaged oz gold and 1130 oz silver the concentrate has averaged oz gold and 1600 oz silver and the bullion has averaged about fine in in gold and silver san francisco de yoquivo the center of the mining district is in the western part of the state of chihuahua mexico about 35 miles west of san juanito on the kansas city mexico orient railroad only one producing company As yet the claims of the yoquivo development company which is the only organization in the district with a record of any considerable production lie within an area roughly one and one half miles square the area extends from the san francisco arroyo north and from the dolores arroyo west and is confined to the andesite formation the yoquivo ore consists chiefly of metallic sulfides sul fides or their decomposition products usually in a gangue of quartz but also as impregnations within the vein material the minerals of the san francisco vein system named in in order of their preponderance are pyrite copper minerals headed by and including malachite and galena usually signifying low gold and silver argentite possibly native silver and gold the gold is probably in the native state the minerals of the C Q don carlos vein systems are pyrite argentite and gold all intermixed with quartz seemingly pure crystals of pyrite assay well in both gold and silver late phases of and galena have been deposited in parts of the don carlos vein the only copper mineral is high t grade samples of ore exhibit beautifully crystallized patterns of quartz heavily charged with argentite and masses of almost pure argentite an inch in diameter have been noted in unique specimens arge argentite etite is plated with a thin veneer of pyrite |