Secondary minerals from old smelter slags from the Puerto de Mazarrón area, Mazarrón, Murcia, Spain.

In the Mazarrón area there are a series of mineralizations of silver-bearing galena that were exploited long before Roman times. Remains of very old smelters are found close to the mines, in the Cabezo de San Cristóbal and in the Coto Fortuna, and also on the coast, in Isla Plana (La Gacha), Cabezo del Castellar and Punta de Nares and Cabezo del Gavilán (or de los Gavilanes), and in Loma del Alamillo. The discovery in 1883 of the Prodigio vein, with a wealth of minerals that lived up to its name, resulted in the construction from The Compañía Metalúrgica de Mazarrón of a new smelter, named Santa Elisa. A major problem of the smelting process was the removal of the huge quantities of slags produced, about 30 tons a day for each furnace.They had to be deposited along the beach, forming an embankment between the salt flats existing at that time and the sea. In the slags are found maru uncommin mninerals. This is the first time that the presence in Spain of pseudoboleite, paralaurionite, ecdemite, fiedlerite, barstowite, fougerite, ludlockite and nealite are described