COTTA ON THE VEIN-FORMATIONS OF THE ERZGEBIRGE. 29 



to the chief direction of the band from north-east to south-west 

 (Standing and Morning veins). Their dip is usually to the north- 

 west. This formation appears in a more isolated manner in some 

 veins in the neighbourhood of Frauenstein, Ammelsdorf, Hockendorf, 

 and Dippoldiswalda. 



The thickness of the veins belonging to this group varies generally 

 between one-tenth of a fathom and a fathom ; some of them have been 

 examined and found rich enough to be worth working for more than 

 800 fathoms in length and above 200 fathoms in depth. In them 

 crystalline, or hornstone-like, white or grey quartz forms the predo- 

 minant filling mass, in which weisserz (argentiferous mispickel), 

 mispickel (without silver), pyrite, blende, galena, but especially the 

 noble silver ores, as the pyrargyrite, argentite, and native silver, fre- 

 quently occur. 



Dolomite, diallogite and calc-spar are also by no means rare, though 

 far from occurring in such abundance as quartz. Less common and 

 always newer constituents are: fluor-spar, barytes,siderite, strontianite, 

 celestine, gypsum, silver-fahlore, fahlore, miargyrite, stephanite, po- 

 lybasite, freieslebenite, earthy sulphuret of silver {Silberschwarz), fire- 

 blende, redruthite, marcasite, brown blende, bournonite, stibine, valen- 

 tinite, kermes, plumosite, haematite and specular iron-ore. 



The quartz of these veins is in general firmly attached to the walls, 

 and frequently encloses fragments of them, which it has surrounded 

 with spheroidal zones of crystals. These veins are very frequently 

 broken up into a multitude of branches, and the numerous veins of 

 the Neue Hoffnung Gottes at Braunsdorf are so remarkable in this 

 respect, that they appear to consist only of a vast network of the most 

 variously ramified masses. 



The veins of the noble quartz formation are the oldest in the vici- 

 nity of Freiberg ; some of them, as the Reinsberg Gluck-Morgen 

 vein, are traversed by porphyry. 



b. The pyritical Lead-formation (the Ziig, Tuttendorf, and Loss- 

 nitz formation of Freiesleben) is especially developed in the neigh- 

 bourhood of the town of Freiberg and to the north-east of it, chiefly 

 in veins, with a strike from north-north-east to south-south-west, and 

 with a dip to the north-west. 



The veins have a rectilinear course, are from two inches to half a 

 fathom wide, and not much divided. They consist predominantly 

 of quartz, with thickly disseminated pyrite, mispickel, black blende 

 and galena, with one to six ounces of silver in the hundredweight ; 

 but the following minerals also often appear in them : dolomite, dial- 

 logite, siderite, fluor-spar, barytes, calc-spar, chlorite, chalcopyrite, 

 pyrargyrite, silver-fahlore, argentite, earthy sulphuret of silver, poly- 

 basite, native silver, cerussite, and pyromorphite. To the east and 

 south-east of Freiberg (for instance in Gottlob Spat near Junge 

 Hohebirke), and also in the district of Hohnstein, a number of veins 

 of this formation occur, which besides pyrite, mispickel, blende and 

 galena, frequently contain also chalcopyrite, redruthite, bornite, fah- 

 lore, azurite, chrysocolla, malachite, cupreous limonite, cuprite and 

 native copper, and thus exhibit the characters of the Freiberg and 

 Hohenstein formation of Freiesleben, or Werner's copper formation. 



