Emilio Mine, Loroñe, Obdulia vein, Colunga, Asturias, Spaini

Regional Level Types
Emilio Mine	Mine
Loroñe	Village
Obdulia vein	Vein
Colunga	Municipality
Asturias	Autonomous Community
Spain	Group of Countries

Although the pithead and part of the mining works of Emilio Mine are located in Colunga, the main works are in Caravia and it belongs to the last locality concerning its mineralization (it is further north mine of the group that comprises Jaimina, Valnegro, Eduardo...). For this reason it is included in Caravia mining area.

This mining concession was demarcated in 1940 at the Mine Office in Oviedo by Francisco Llera Bárcena, inhabitant of Colunga, for the extraction of kaolin. It then seems that, after some obscure political pressure, the rights were transferred to another owner who conducted research during 1947 that led to the opening of a 42m deep shaft. From this shaft they extracted mineral with limited technical resources until 1950. In 1965, after the renovation of the shaft, research confirmed the existence of a 500m long mineralized vein, in a NW-SE orientation, with an average width of 1.5 m. At about that time Minera Togar (Tomás Garcés de los Fayos) acquired the operation and the benefits from it, selling the unprocessed mineral to companies such as Fluoruros or Minersa, for its concentration, or directly as a metallurgical product to several Asturian and Basque foundries. By 1982, with the decline of Togar mining company and its progressive economic dependence on Minersa more evident, this latter company leased the operation and planned a wide investigation campaign that revealed the existence of large reserves of fluorite in the deposit. With the experience accumulated in mines such as the Cucona or Moscona, the company established an extraction system using underground mining through chambers and pillars. All this development finished with the purchase of every asset and the concessions of Minera Togar by Minersa. The mining works were then restarted in 1985, with Minersa locating at the mouth of the mine a crushing and ore pre-concentration plant where the ore was prepared before being transferred to the flotation plant that the company also owned in Torre. Since 1985 about 4 million tons of mineral have been extracted and the galleries made reach more than 60km in length. As a curiosity the change of the extraction from kaolin to fluor spar was finally made by Minersa in 1989.

Regarding mineralogical features this mine is well known internationally. Since the beginning of the 1980’s it has been providing outstanding specimens of fluorite whose crystals have colors varying from colorless to deep violet. This fluorite is frequently associated with calcite, baryte and quartz. They also display a special characteristic, a true hallmark of the specimens coming from Emilio Mine: the great variety of the habits and combinations of the isometric system that occur in the mineral crystals. This varied crystallography is also typical of the whole Caravia mining area, although in Emilio Mine shows the widest range of possibilities. Another distinctive feature of this locality is the existence of sulfides inclusions (cinnabar, sphalerite, pyrite, chalcopyrite, etc.) inside the fluorite crystals, and it is also common to find organic inclusions (hydrocarbons) and even solid carbon remains. Over the the last years, from 2005 to 2009, while crossing the region known as intermediate zone, many pockets were found, some of them large, with double terminated big quartz crystals (up to 20 cm.), frequently associated with calcite, fluorite and pyrite, with good transparency and luster, often displaying window shape growths on their faces.

Other Regions, Features and Areas containing this locality

References