Guanajuato, GTO, Mexico

     This district is located 274 kilometers (173 miles) northwest of Mexico City and is southeast of Leon. When the Spanish explorers first arrived in 1548, they found the remains of earlier Otomi workings on the veta (vein) Peregrina. Later discoveries established what was to become one of the richest mining districts in the world. Some estimates for silver production over it's history is one-sixth of all silver produced in the world. Today production of the district is very low.  The veins are poddy and irregular and very hard to predict.
    This fall the La Sirena and Torres Mines were closed by Penoles. Increased metals prices may get these mines reopened in the near future.
    The Rayas, Cata and Valenciana mines are now producing specimens but in lower volumes than the past. Very nice K-feldspar adularia (valencianite) with quartz are available in all sizes. Some very nice classic amethyst are coming out, never in any quantity, but very desirable. 
 


The 31 meter buttresses of San Juan de Rayas mine


  Note:  Polybasite and Pearceite are solid solution series. Most specimens are not end members, but are somewhere in between. Therefore most of these are not analyzed and are labeled Polybasite-Pearceite.
    It is difficult to predict what the future may bring, so stay tuned for future updates

The Tiro General (main shaft) of the San Juan de Rayas mine. It is octagonal and measures 12.2 meters in diameter. The hoist house is behind it.

GTOCA-01.jpg (46366 bytes) GTOCA-01- 4cm x 5cm - Calcite, Peregrina Mine, Guanajuato. 3% - 5% manganese content gives a slight pink tint to this lustrous opaque crystal and causes the bright fluorescence. 
GTOPY-01.jpg (63217 bytes) GTOPY-01 - 4cm x 5cm - Pyrite on Dolomite pseudomorphing calcite with selenite. La Sirena Mine, Guanajuato. The dolomite shell shows the late stage dolomitization  that is typical for this district.  
GTOPY-02.jpg (52397 bytes)
GTOAC-01.jpg (47360 bytes) GTOAC-01 - 8cm x 8cm - Acanthite paramorphing Argentite, Level 590, La Sirena Mine, Guanajuato, GTO, Mexico. Lustrous little crystals of acanthite contrast nicely against the snow white background of calcite. I just don't see many matrix specimens like this.   

Gallery 2  Ojuela Mine, Mapimí, Durango, Mexico
Gallery 3  Santa Eulalia, Chihuahua, Mexico
Gallery 4  Minerals Page 1
Page 2      More Minerals
Gallery 5  Hydraulic Rock Trimmers