ITALIAN LOCALITIES. 35 



its near Agordo are in . the same series of rocks and at no great distance. 

 Tlie production of the Venetian mines has n(;ver been large and of late 

 years lias become insignificant. Some data are given in Cliapter I. 



Traces of cinnabar are found in Lombardy in quartzite, but the quantity 

 is nowhere considerable.^ 



In Tuscany numerous deposits of quicksilver occur in a belt about 

 one hundred and twenty-five miles in length, running parallel to the west 

 coast and at an average distance of about twenty miles from the ocean. 

 The southern end of this series of deposits is at Mt. Amiata. The Levigli- 

 ani mine, near Serravezza, at the northern end of the belt, was known as 

 early as 11 63. The cinnabar is accompanied by guadalciizarite, siderite, 

 and pyrite in a quartz gangue and occurs in steatitic schists in small irregular 

 veins. The chief mines of this belt are at its southern extremity. Amiata 

 is a great trachytic mass resting upon rocks which are Post-Jurassic and 

 probably Eocene. They are for the most part calcareous. All around the 

 edge of the lava and in the Eocene rocks occur quicksilver deposits, many of 

 which have been exploited. Mr. B. Lotti also found cinnabar in the trachyte 

 itself, near its edge, showing that the deposits are later than the erui)tion. 

 The principal mine is the Siele, about five kilometers from Selvena. This, 

 as described b}- d'Achiardi, is sunk on a stratum of marl many meters in 

 thickness, which is impregnated with cinnabar. Stringers of calcite, spotted 

 with cinnabar, are frequent in this deposit. The same author gives geolog- 

 ical notes on several Italian mines not mentioned here. 



Cinnabar occurs at La Tolfa, not far from Civita Vecchia, associated 

 with fluor-spar and blende. 



Noggerath writes: "At Vesuvius the occurrence of quicksilver is very 

 doubtful. J'r. Hoffmann, in his history of geognosy, speaking of the 

 products of Vesuvius, says that among the metallic substances Dolomieu 

 mentions also quicksilver and stibnite, but they have never since been found, 

 as Breislack explicitly states ; hence an error seems to have been made here." 

 On referring to Hoffmann's history- it does not appear to me that he intends 

 to asci'ibe to Dolomieu the assertion that at Vesuvius he fouhd quicksilver. 



' A. d'Achiardi, loc. cit. 



'Gescbicbte der Geoguosie uud Schildoruug der vulkaiiiscbcu Ersclaciuuugen, Beiliu, 18:J8, p. 477. 



