148 ORIGIN AND MODE OF OCCURRENCE OF GOLD-BEARING VEINS. 



the country rock. The crystalline schists are traversed in the 

 locality by dykes of finely granular granite, and it is said to be 

 only in the vicinity of these that the quartz veins are found 

 to be productive. The granite near the auriferous veins is 

 impregnated with iron pyrites, which has become partially 

 converted into brown iron ore. The average yield of gold from 

 these veins is about 8 dwts. to the ton. The gold is accompanied 

 by galena, grey copper, and other minerals, including native silver 

 and bismuth ochre. 



An essay on the peculiarities of gold veins would not be 

 complete without mentioning those of Transylvania in Hungary. 

 The most remarkable of the auriferous deposits of that part are 

 to be found at Voeroespatak, and they may also be classed amongst 

 the most remarkable and interesting in the World, and some of 

 them have been worked for a period said to date back to the time 

 of the lloman Empire. A description of the principal workings 

 in Voeroespatak is as follows : — A Mount called the Csetatye,, 

 composed of a decomposed igneous rock probably propyl ite, is 

 surrounded by tertiary sandstones of Eocene age. In this 

 Mount a large lode formation occurs consisting of a perfect 

 network of veins. These veins are of the character of true fissure 

 lodes, and they pass out of the igneous rock into the tertiary 

 sandstone, and are prolific in both. The sandstone in the near 

 vicinity of the Csetatye Mount is much silicified and interbedded 

 with tufa strata and conglomerates. Upon the top of the Mount 

 is a large excavation made probably in the time of the Romans, 

 and immense cavernous workings exist underneath. The lode 

 matter thus worked consisted of a network of veins containing 

 gold both in them and in the intervening country rock. These 

 veins are said to have been nearly vertical and irregularly 

 columnar ; they consisted of quartz, calcspar, and iron pyrites, 

 and sometimes of diallogite, and contained gold in minute grains 

 or in a crystallized state. Some of the diallogite veins are found 

 at times perfectly permeated with crystalline gold, and when cut 

 and polished have a beautiful appearance. Blende, tetrahedrite, 

 and many other minerals are found associated with these veins, 

 and the whole mountain is impregnated with metallic sulphides, 

 chiefly iron pyrites. 



The telluric veins (called locally " clifts ") of this district are 

 also remarkable as containing sylvanite, nagyagite, and other 

 telluric minerals, with native gold, galena, blende, stibnite, 

 pyrargyrite, and native silver, the principal gangue being quartz 

 and diallogite. They are said to be richest in a slightly decomposed 

 rock, but fall off in richness both when the rock becomes much 

 decomposed or not decomposed at all. They exist principally in 

 the igneous rock propyl ite, but segregation veins also occur in a 



