La-Croix-aux-Mines, La-Croix-aux-Mines District, Vosges, Lorraine, France

The discovery of silver-bearing veins in the area of La-Croix-aux-Mines dates back to the 9th century. There were some mining activities in mediaeval times, but it was not until the 15th century that the deposit was developed at a larger scale. Mining continued until the 16th century and came to a first halt due to several political crises in Central Europe. In 1720, the mines were re-opened, but already forced to close around 1760, after a series of fatal accidents. After a long period of inactivity during the 19th century, the mines were re-opened again in 1924 and finally closed in 1948. By this time, the main vein had been explored on a length of 260 m and to a depth of 140 m below surface level. The total output of the mines amounts to around 100,000 tons of lead and 150 tons of silver.

The main vein of La-Croix-aux-Mines represents a tectonically brecciated zone with a width of up to 100 m, that is hosted by strongly altered gneisses and granites. Within this zone, richly mineralised NW-SE trending veins alternate with poorly mineralised NE-SW trending ones and N-S trending veins of barren gangue material, making the deposit appear as to consist of stockworks. The most abundant ore was argentiferous galena, including varying amounts of fahlores, chalcopyrite, pyrite, marcasite and bournonite.

Ref.:
- Palache, C., Berman, H., & Frondel, C. (1951), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, Volume II: 893.

- Bari, H. (1982). "Le plus gros filon plombifère de France: La Croix aux Mines (Vosges)." Minéraux et Fossiles, 83,pp:31-40.

- Hohl, J.-L. (1994). "Minéraux et Mines du Massif Vosgien", Editions du Rhin (Mulhouse).