On the Paragenetic Relations of Minerals. 363 



wad — the usually accessory derivatives of this mineral, — 

 barytite is, in all instances, more recent than spathic iron or 

 brown iron ore, and lies in numerous veins in them. 



The fahlerz and copper pyrites belong only or principally 

 to lodes in zechstein above the cupreous slate, and the fah- 

 lerz has most likely not often been found without a covering 

 of heavy spar. Here, as in all other formations, it has been 

 found that it is richer in silver when accompanied by little 

 or no copper pyrites. The galena, which occurs very 

 rarely indeed, may perhaps be referred to the same date as 

 the fahlerz. If, then, the barytite is taken as the boundary, 

 two formations must be distinguished in the lodes, — that of 

 fahlerz and that of cobalt and nickel minerals, even although 

 they may be very closely connected. This distinction is 

 supported by the circumstance that barytite has not been 

 deposited upon the first formation until after the fahlerz has 

 suffered decomposition. Consequently, the constituents of 

 the fahlerz must have first been set in motion, and those of 

 the cobalt and nickel minerals afterwards. 



Sometimes the minerals whose formation has preceded 

 that of the barytite are mixed up together with those which 

 have been formed subsequently, partly in a fractured state, 

 and even so-called spheroidal masses are found ; phenomena 

 which undoubtedly indicate violent disturbances of the lodes. 

 At the Neidhammeler-zuge, near Saalfeld, fragments of fer- 

 ruginous zechstein are surrounded by fahlerz, copper 

 pyrites, barytite, and then the numerous decomposition pro- 

 ducts, ferruginous copper green, copper lazure, malachite, 

 erythrine, kupferschaum, &c. Yellow and brown earthy 

 cobalt and copper — manganese ore likewise occur here, — and 

 these originated either from the hardening of mud, or are de- 

 composition products, — and ochery hydrated oxide of iron, 

 impregnated with oxide of cobalt. Even metallic copper has 

 in some rare instances been found in spike-shaped distorted 

 crystals, entirely surrounded by brown iron ochre. 



In the riicken of Schweina and Gliicksbrunn spies cobalt 

 is the only abundant primitive mineral of the cobalt nickel 

 formation ; roth nick elkies with chloanthite is rare. Bis- 

 muth appears to be entirely wanting. The lodes, moreover, 



