Tavagnasco Mines, Tavagnasco, Metropolitan City of Turin, Piedmont, Italyi

Regional Level Types
Tavagnasco Mines	Group of Mines
Tavagnasco	Commune
Metropolitan City of Turin	Metropolitan City
Piedmont	Region
Italy	Country

Lodes of mixed sulfides (Pb, Bi, Zn, As, Fe, Cu) in quartz-siderite gangue, embedded in micaschists of the Sesia-Lanzo Zone, on the northeastern flank of Monte Gregorio at elevations above 600 m a.s.l.

According to Froment (1899a, b), 16 lodes are present in the area of the former mining concession, extending from the left side of Rio Piovana (Briasse) to the right side of Rio Bosco across the valley of Liva brook: St. Jean, Briasse, St. Joseph, Genoveffa (Geneviève), Aquila, Ste. Catherine, Parella, Rosa, Ste. Anne, Belvédère, Espérance, Pauline, Piaunetto, Liva, Pary, and Feipian. St. Jean is the lowest of these lodes, Briasse the southernmost, and Feipian the highest. The ore bodies are related to a system of fractures having NE-SW to E-W strike, dipping NE to N with dip angles up to 60°; a second vein system oriented NW-SE, dipping towards NE with dip angles up to 40°, intersects the first one, giving rise to a stockwork deposit (Matteucci & Zucchetti, 1962; Mastrangelo et al., 1983).

The primary ore mineral assemblage consists of sulfides (sphalerite, galena, arsenopyrite, pyrite, pyrrhotite, chalcopyrite, and bismuthinite), accessory sulfosalts (bournonite and tennantite), and native gold. Gangue minerals are represented by quartz and siderite (Mastrangelo et al., 1983). Minor amounts of Pb-Bi acicular sulfosalts have been recently identified. The sulfide assemblage is locally altered and Cu-Pb-Bi secondary minerals occur (such as anglesite, azurite, langite, several Bi compounds, etc.).

According to fragmentary historical information a mining concession for lead was granted in the 1730s to the Marquis San Martino de Parella and an unsuccessful attempt to mine an ore vein for silver at Vallereis took place in 1847, after the more than a century-long dispute over land and mining rights between the local community and Count Giacomo Filippo Setto (died in 1747) and his successors.
According to the documents preserved at the State archives of Turin, prospecting permits were granted from the second half of the 1800s at the following localities: Fey Piani for Fe, Pb, Cu, Au, and Ag (1872); Chiosi or Foini for pyrite, Cu, and Ag (1874); Pino or Chiapei for Ag and Pb (1876); Vallereis for Au, Ag, Pb, and Cu (1886); Feipian for pyrite and chalcopyrite (1893); Getti and Vallereis for arsenopyrite and galena (1896); Barzino and Li Piani for Fe and Cu (1900).
A mining concession named Getti and Valleris was granted in 1897 to Stefano Serra, who sold it a few months later to Alcide Froment, founder of the company “Société générale des Mines de Liva et de Tavagnasco”. The real exploitation begun only in 1900 at Aquila lode, but in 1904 the concession was revoked (Rocchetti, 2009). Some small-scale works were done on the Tavagnasco lodes before the 1950s.

Note on the ciriottiite occurrence:
Analysis recently carried out on more than thirty samples, all from the Espérance tunnel, with different morphologies (acicular crystals, whiskers, fibers, skeins, "linear ribbons", elongated microcrystals, linear or twisted filaments, plot, weaving, interlacement, intertwinement, mat and long or slightly hinted tubes, etc.), has demonstrated the extreme rarity of the ciriottiite.
Only six samples were found to have a chemical composition in accordance with that of the ciriottiite but, due to the small and / or very fine filaments or to the tubular morphology, no attempt was made to detect the cell parameters.
All the very few chemically certified samples of ciriottiite come from a very limited portion of the Espérance lode.
Without conclusive analysis it is impossible to attribute the identity of the samples.

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