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Italy is classic sulpur country ! The once famous sulphur mines of Sicilia have been mined by the Romans and probably also by the Carthagians before. But beside Sicily there are more prominent italian sulphur mining districts like Formignano near Cesena, which stayed in production for 500 years and the Perticara mines near Novafeltria. All of these mines have produced superb specimen of native sulphur, but despite the remarkable beauty of the sicilian specimen it was Perticara, which supplied the largest sulphur crystals known to exist.
Despite the fact, that there was a "sulphur outcrop" along the strike of the sulphur rich layers, mining started surprisingly late in Perticara, possibly due to its remoteness in a rather montaineous terrain. The first mining lease dates to 1741, which is much later than all other italian sulphur mines. Soon a large network of shallow shafts, levels, stopes and several "discenderias" (inclined adits) were established and mining begun in earnest. The heydays of the Perticara mines were in the second half of the 19th century and the first decades of the 20th century. After the second World War the mines dwindled until their final closure in 1964.
The mines in Perticara where rather shallow with the deepest shaft reaching a mere 60 m, whereas the Maestro Layer = the main sulphur bearing layer reached a thickness of up to 22 meter. Sulphur occured in paragenesis with gypsum, calcite and celestite in a sucession of sometimes heavily folded marl and limestone of upper miocene age. The origin of the sulphur is still in dispute, as the surrounding miocene rock is a more or less ordinary gypsiferous limestone, giving little clues to the formation of several million tonnes of native sulphur...There is however a remarkable high amount of bitumen in the rocks and some of the most spectacular sulphur crystals were found in cavities filled with more or les liquid bitumen.
Spectacular sulphur crystals were found in abundance in the Perticara mines, showing a very large variety of shapes and habits. The magnificient crystal drawings of BOMBICCI (1895)give an impression of the diversity of the sulphur crystals : we find tabular, blocky, needle like, prismatic shapes as well as pesudo - scalenohedrons. Many crystals show peculiar pitches in their faces or sceletal growth, probably formed by rapid crystallization. The colour of the crystals show all shades of yellow to brown, the latter caused by ubiquitous bitumen inclusions.
Large aggregates of sulphur crystals have been found at Perticara as well as large, if not giant single crystals. The largest one is a 24,5 x 18 x 13 cm large, blocky giant, now housed in the Collection of the Museum of Natural History in Milan (see photo). Not only it is the largest sulphur crystal known to exist, but also the largest known crystal of a native element as such. Other, similiar large sulphur crystals are known, one of which with 22,5 x 16,5 x 11 cm was mentioned by RICKWOOD (1981) in his famous publication about the largest crystals.
Since many years there was a small exhibition on place about the Perticara mining heritage. In summer 2005 these exhibition was replaced by a modern museum complex called Museo Storico Minerario di Perticara, which gives an excellent and in-depth overview about these once famous mining district. The author of these text visited the place and the museum some weeks before its formal opening and hence is unable to say, if any of the large sulphur crystals can be seen there. Maybe a more recent visitor of the museum can tell ?
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Perticara native sulphur in a nutshell :
Mineralogy : |
Sulphur crystals with gypsum, calcite, celestite and bitumen. |
Crystal Size : |
Crystals up to 25 cm are preserved in museum collections, even bigger ones have most probably been found during the mining operations. |
Geology & Origin : |
The sulphur rich deposits occur in young tertiary strata of upper miocen age. The origin is uncertain, but probably linked to bacterial oxydation of gypsum rich layers. Ocassional sceletal growth indicate at least some hydrothermal influence. |
Status : |
Abandoned mine, part of which was recently converted into a mining heritage & mineralogy museum. |
Remarks : |
Largest known single crystals of sulphur and also of a native element as such.
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Other notable & famous native sulphur occurences :
- The most famous sulphur deposits of all are certainly the old sicilian sulphur mines like Agrigento, Racalmuto and Caltanisetta, which have been worked from roman times until the early 1980s. They produced many thousands of superbly crystallized sulphur specimen.
- Another well known european source, which was worked up to the present, are the sulphur mines of Silesia, Poland, namely the Machov mine, which produced many nice sulphur - celestite specimen.
- A unique occurence is a several 100 m long "sulphur stream" produced by fumarolic activity of the Shiretoku volcano, Hokkaido, Japan
- Excellent sulphur crystals up to 10 cm are known in great numbers from the El Desierto deposit, S of Salar de Empexa, Bolivia
- Remarkable sulphur stalactites up to 1 m size and longer are formed in abundance by recent fumarolic activity of the Ijen Volcano in Eastern Java. This crater is actively mined for sulphur by the locals !
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The Vittoria shaft at Perticara, now part of a mining heritage museum
Photo : unkown
Largest known sulphur & native element crystal, 24.5 cm high,
at the Museum of Natural History, Milan. Click image for magnification
Photo : Roberto Appiani
Plate depicting Cabernardi (Perticara) sulphur crystals, from Bombicci (1895). Click image for magnification
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Resources and relevant weblinks :
In 2005 a new major museum - Museo Storico Minerario di Perticara - devoted to the mining heritage and geology & mineralogy of the local sulphur deposits was inaugurated in Perticara, which is well worth a visit. Its website can be found here.
The best collection of the famous large sulphur crystals is housed by the Natural History Museum of Milan, which apparently do not have a current website.
There is an excellent paper about Perticara with lots of images and some more plates of BOMBICCI (1895) as well as more important references in the Mineralogical Record :
GUASTONI, A. & PEZZOTTA, F. (2002) :
Sulfur from the Perticara mine area, Pesaro-Urbino, Italy
Mineralogical Record, Vol. 33, No. 4, pp. 305 - 320
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