The mercury deposit of Levigliani is hosted within phyllitic and metavolcanic rocks of Middle to Upper Ordovician age (metasandstones, quartzites and phyllites with carbonate-chloritic phyllites levels and calcalkaline metabasites), which were intensely deformed and metamorphosed to the greenschist facies (about 0.3-0.4 GPa, 350°-370°C) during both the Hercynian and the Tertiary Appenninic orogenies. Levigliani deposit reached the present structural arrangment during a syn-tectonic and syn-metamorphic process of mineralization. Levigliani probably represents a pre-Hercynian concentration of mercury sulphide, which survived through Hercynian and Alpine tectono-metamorphic events.
An unique mineralogical situation exists in the Cavetta tunnel, where some decimetric to metric quartz-carbonate veins contain widespread cavities completely or partially filled by native mercury with the walls of the cavities covered by millimetric crystals of cinnabar, pyrite, mercurian sphalerite ... Usually their size does not exceed a few millimeters but in the 18th century were found some very large cavities, containing about 1 tons of native mercury.
Hg mineralization is associated with carbonate-chloritic levels and it occurs as disseminations or as quartz-carbonate veins. Disseminated mineralization is constituted of small levels of cinnabar, flattened along S1; this kind of ore is isoclinally deformed by D1. Dini et al. (2001) report the presence of two generations of veins; the early ones are folded, with axial plane parallel to S1. A later generation of veins was emplaced along extensional fractures, controlled by D2 structures.
In both mineralizations, Dini et al. (2001) recognize two different assemblages:
- A-type: cinnabar I, zincian metacinnabar and pyrite. This assemblage is equilibrated at P-T conditions close to the metamorphic peak of Apuane Metamorphic Complex (P = 0,3-0,4 GPa; T = 350-385°C).
- B-type: cinnabar II, mercurian sphalerite, pyrite, native mercury, chalcopyrite, galena and pyrrhotite. B-type assemblage is present exclusively in the late stage veins of Cavetta adit. According to Dini et al. (1995), B-type assemblage partially overprinted and replaced A-type assemblage during the retrograde stages of metamorphism (T less than 250°C). Grumiplucite is present in this kind of assemblage.
NB: Weddellite previously described as unconfirmed species present at "Cavetta" tunnel is now considered not existent. Also Metacinnabar does not occur in the "Cavetta" tunnel, but is present in other parageneses at Levigliani mine [Ref.: Batoni, M. & Ceccantini, L. (2007): Errata corrige: Levigliani. Solo cinabro alla "Cavetta". Micro (località), 1/2007, 179-179].
References:• D'Achiardi A., 1872/73. Mineralogia della Toscana. Arnaldo Forni Editore, Pisa.
• D'Achiardi A., 1876. Su di alcuni minerali toscani. Guadalcazarite di Levigliani. Atti Soc. Tosc. Sci. Nat., Mem., 2: 112-113.
• D’Achiardi A., 1877. Miniere di mercurio in Toscana e considerazioni generali sulla genesi loro. Atti Soc. Tosc. Sci. Nat., Mem., 3: 133-149.
• Manasse E., 1920. Sulla leviglianite. Atti Soc. Tosc. Sci. Nat., Mem., 33: 156-163.
• Zaccagna D., 1932. I giacimenti ferriferi di Monte Tambura e Fondone e Fornovolasco, piombo argentifero di Bottino e Valdicastello, rame del Frigido e di Vagli, mercurifero di Levigliani e Ripa. Mem. Descr. Carta Geol. Ital.: 390-403.
• Carmignani L., Dessau G., Duchi G., 1972. I giacimenti delle Alpi Apuane e loro correlazione con l'evoluzione del gruppo montuoso. Mem. Soc. Geol. Ital., 11: 417-431.
• De Michele, V. (1974). Guida mineralogica d'Italia. Istituto Geografico De Agostini, Novara, 2 vol
• Gallerini L., Gallerini P., 1975. Ritrovamento di un cristallo di cinabro alla miniera di Levigliani. Notiz. Gr. Mineral. Fiorent., 2: 8.
• Brizzi G., 1977. La miniera di Levigliani. Notiz. Gr. Mineral. Fiorent., 4, n. 1: 20-22
• Carmignani L., Dessau G., Duchi G., 1978. Structural control of mineralization in the Apuan Alps. Verh. Geol. B-A, 3:279-283.
• Dini, Benvenuti, Lattanzi, Tanelli (1995): Mineral assemblages in the Hg-Zn-(Fe)-S system at Levigliani, Tuscany. European Journal of Mineralogy, 7, 417-427.
• Dini A., 1995. Metacinabro zincifero (leviglianite) e sfalerite mercurifera della miniera di Levigliani (Alpi Apuane, Toscana). Atti Soc. Tosc. Sci. Nat., Mem., 102: 67-72.
• Orlandi P., Dini A. , Olmi F., 1998. Grumiplucite, a new mercury-bismuth sulfosalt species from the Levigliani mine, Apuan Alps, Tuscany, Italy. Canad. Miner., 36: 1321-1326.
• Dini A., Benvenuti M., Costagliola P., Lattanzi P., 2001. Mercury deposits in metamorphic settings: the example of Levigliani and Ripa mines, Apuane Alps (Tuscany, Italy). Ore Geology Reviews, vol. 18, issue 3-4; october 2001
• Batoni, M. & Ceccantini, L. (2004): La miniera di Levigliani, Lucca, Toscana. Micro (località), 2/2004, 41-54.
• Batoni, M. & Ceccantini, L. (2007): Errata corrige: Levigliani. Solo cinabro alla "Cavetta". Micro (località), 1/2007, 179-179.
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http://www.strahlen.org/vp/it/levigliani/ 21 entries listed. 20 valid minerals. 1 type locality (valid mineral).
