Notices of the Geology and Mineralogy of Sicily. 205 
crater of Autna. Great quantities of gypsum are used in 
stucco, particularly at Catania. 
Fluor Spar is found in small pieces confusedly crystal- 
- lized, in the mountains of Judica and Torcisi; colour cine- 
reous or violet; rare. 
Barytes, very common; in a'most all the sulphur mines, 
and as the matrix of the ores of copper, lead and silver, at 
the foot of the mountains of Pelorus. Carbonate of Ba- 
rytes in the sulphur mines of Asaro and Raddusa, in small 
scattered grey masses; in the lead ores at Fiume di Nisi, 
yellowish. 
Sulphate of Barytes, very common, alone, or united me- 
chanically with carbonate and sulphate of lime; earthy in 
the sulphur mines of Riesi, sometimes very hard and fine 
grained; crystallized in the sulphur mines on masses of 
the compact variety, and of carbonate and sulphate of lime, 
clay, &c. At Raddusa they find masses incrusted with 
confused crystals, resembling stalagmites. Fetid sulphate 
in the sulphur mines; some large laminar masses have the 
lamine covered with shining black dendrites. 3 
Strontites. The sulphate is found in all the sulphur 
mines, in confused crystals, on the masses of sulphur and 
sulphate of lime; also, in yellowish white, fibrous, amor- 
phous masses, always associated with sulphur and gypsum. 
Carbonate of Strontian, in the sulphur mine of Asaro, in 
amorphous masses, grey, with a brilliant scaly fracture. 
Quartz, in veins in the granite, gneiss, argillite, &c. in 
rolled pieces and fragments at the foot of the mountains of 
Pelorus; also, in beds of rolled pieces and pebbles, in the 
chalk and limestone mountains. Sometimes traversed by 
veins of calcareous spar. Compact schistose masses cf 
white and violet quartz are found in the streams at the foot 
of the mountains of Pelorus; also, irregular pieces of trans- 
lucid quartz, having a tendency to the pyramidal form. In 
the mountains of Judica and Torcisi are friable masses of 
violet quartz, composed of an aggregate of irregular prisms. 
Very minute perfect crystals of transparent quartz, in the 
paste of the marbles of Taormina. Stliceous Slate, in the 
limestone mountains of Taormina, in inclined strata, 
opaque, imperfectly conchoidal fracture, colour smoky. 
Flint, in scattered, rolled pieces, in the limestone moun- 
