Miniera del Siele

Useful Information

Location: Off the road from Piancastagnaio to Castell'Azzara. 1 km south of bus stop Miniere Argus, turn east on single lane road. Signposted. (42,78882222° N, 11,66256389° E)
Open: only after reservation.
Classification: MineMercury Mine
Light: LightIncandescent Electric Light System
Guided tours:
Bibliography: M. Petiton (1880): Note sur la mine de mercure du Siele (Toscane), Ann. Mines, Paris.
E. Rosselli (1890): La miniera cinabrifera del Siele, Atti Soc. Tosc. Sci. Nat., Mem., 11: 78-90.
C. De Castro (1914): Le miniere di mercurio del M. Amiata, Mem. descr. Carta Geol. Ital., 16: 1-270.
S. Zucchetti (1965): Confronto fra i giacimenti mercuriferi primari del M. Amiata e della Spagna, Boll. Ass. Min. Subalp., 2: 49-74.
Address: Miniera del Siele, Piazza Castello, 12, 53025 Piancastagnaio SI, Tel: +39-0577-788004.
Giuseppe Ronchini, Mobile: +39-327-112-3568, Tel: +39-0577-787-181-405. E-mail:
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
Please check rates and details directly with the companies in question if you need more recent info.


1846 beginning of mining.
1865 mine sold.
1867 mine reopened.
1974 mine closed



The Miniera del Siele was named after the Siele valley, which is quite remote. Until today there is only a rough gravel road through this valley and it is reached from the Santa Fiora Castell'Azzara provincial road, turnoff at the Terni crossing. A few years ago you could drive along this road and visit all the abandoned mining sites, but the reclamation of the area is now completed and as a part in this process some mining related sites were opened to the public. Unfortunately the others were either filled in or locked.

Siele Mine was the first Italian mercury mine opened in 1846 and producing the first mercury in 1847. In the same year the Stabilimento mineralogico Modigliani (Modigliani Mineralogical Plant) started operation in Livorno and processed the cinnabar ore. At first the operation required heavy investments and achieved meager economic results. The company went corrupt in the late 1850s and the owners, Cesare Sadun, Angelo Modigliani and Salomone Modigliani ahd to sell it in 1865. It was purchased by the rich trader Emanuele Rosselli from Labronica. With the money of Sara Levi Nathan, the widow of a rich London banker, he reopened the mine and production became successful.

In the mines in this area cinnabar was mined, a mercury ore which forms beautiful and deadly red crystals. The mining was lucrative but also extremely dangerous, mercury poisoning was a normal occupational disease. The mined cinnabar was processed in the mine plant primarily by heating, the mercury vapour was then condensed. The mercury was sold for the production of precision instruments (barometers, thermometers, etc.), for priming weapons, tanning leather, and the manufacture of anti-mold paints. Also there were pharmaceuticals, pesticides, mercury vapor lamps, and much more for which merury was required. With increasing uses for mercury, the profits became bigger and bigger.

But the success attracted a large number of industrialists and financiers and from 1870 numerous cinnabar mines on the cinnabar field on Mount Amiata. This was later called the corsa al mercurio (race for mercury). The next opened mines were miniere delle Solforate, miniere del Cornacchino, miniere del Morone, miniere della Senna, miniere di Casa, miniere di Paolo, miniere di Scansano, miniere di Paolodi, and miniere Cortevecchia, just to name a view. The investors were from all over Europe, Germany, France, Poland, and Italy. The mines flourished but most were closed in the aftermath of the global financial crisis of 1929.

An exception to all other mines was the mine which was founded in 1897 in the town Abbadia San Salvatore. It was operated by the Società Anonima delle Miniere di Mercurio dell’Amiata, an company founded by Vittorio Emanuele Rimbotti and undisclosed financiers from Freiburg in Germany. This mine became the second biggest producer of mercury in the world in the 1920s after the mine in Almaden, Spain. You can vist the MineMuseo Minerario di Abbadia San Salvatore if you are interested.

At the same time the Siele Mine flourished too, the construction of Cermak-Spirek ovens, the introduction of the steam engine, and the discovery of a rich deposit of cinnabar were important factors. But this ended with the fascist racial laws of 1938. The Jews were deprived of all rights of citizenship including the possession of property After 70 years of ownership they were forced to sell their mine.

Mining finally ended in 1974 and the town Siele, which was a functional mining town but also home to thousands of miners and their families was abandoned. After decades of neglect the problem of the mercury rich slack heaps became quite urgent and the are was reclaimed

Some buildings were recovered, the Pacific ovens, the cinnabar shattering building, homes of technicians and managers, and the church. One building will contain the future archives and multimedia rooms. And finally there is the villa that hosted the Rosselli family. During the process the tunnel of the Galleria Emilia was developed for tourist visits. It ends at the Raffaello shaft, which is one of the deepest going down 350 m.