40 QUICKSILVER DEPOSITS Ol<' THE PAOIFU; SLOPE. 



quantities, especiallv at contacts with the Carboniferous beds. Pyrite is 

 tolerably abundant, sometimes associated with metallic mercury. No other 

 metalliferous mineral occurs. The usual gangue minerals are quartz, cal- 

 clte, and dolomite, and they have been deposited simultaneously with the 

 cinnabar. Idrialite occurs in slia])eless masses and is especially associated 

 with hepatic cinnabar. In one region a small (piantity of fluor-spar lias 

 been detected with cinnabar and dolomite. Mr. Lipoid regarded the asso- 

 ciation of minerals and the manner of their occurrence as conclusively 

 proving that the ore had been deposited from fluid solutions, a conclusion 

 wliicli ai)})ears to me entirely justifiable. 



This mine, unlike others in southern Austria and northern Italy, grows 

 richer as its depth increases, and the known reserves in 1880 were sufficient 

 to maintain the production at the current rate for over seventy years. 



There are noteworthy analogies between this mine and that of 

 Almaden. In the latter the ore occasionally crosses strata, though usually 

 following the stratification. In both, reticulated deposits are found, though 

 at Idria the reticulated mass is irregular in outline, while at Almaden it is 

 tabular. PN-rite is the only foreign metallic mineral abundant in either 

 deposit. In both a part of the deposits follow the stratification and in 

 both there is evidence of disturbance preceding ore deposition. Impreg- 

 nations occur in sandstone in each mine. Both deposits grow stronger as 

 the depth increases. Thus, wdiile the general impression produced by the 

 two chief mines of cinnabar is different, the ditference is one rather of de- 

 gree in the development of particular features than of fundamental char- 

 acter. Cinnabar is also found at many points in Carniola, Styria, Carin- 

 thia, Salzburg, and the Tyrol. At a number of these localities small quan- 

 tities of quicksilver have been produced, but none is commercially im- 

 portant. The mode of occurrence, so far as known to me, is in each case 

 similar to that of other deposits more or less fully described in this review. 



In Bohemia cinnabar, quicksilver, and calomel are found with iron 

 deposits. At Horowitz the quantities obtained were so considerable that 

 from time to time a few hundred-weight of quicksilver were produced as an 

 incident to the production of hematite. The latter forms a bed in Silurian 

 schists, while the cinnabar, accompanied by heavy spar and pyrite, is found 



