ORDER xci. DODECAHEDUAL GAUNET-BLENDE. 35 



2. According to THOMSON and GUENIVEAU, it consists of 



Zinc 59-09 62-00. 



Iron 12-05 1-50. 



Sulphur 23-86 34-00. 



Its chemical formula is Zn S 2 , agreeing with 66-J2 of zinc 

 and 33-28 of sulphur. When strongly heated in the oxi- 

 dating flame of the blowpipe, it gives off vapours of zine, 

 which form a coating on the charcoal, but it does not melt. 

 It is soluble in nitric acid, during which process sulphuret- 

 ted hydrogen is disengaged. 



3. Dodecahedral Garnet-blende is frequently found in 

 nature; but all its varieties are not equally common. It 

 is met with in beds and veins, accompanied chiefly by hexa- 

 hedral I^ead-glance, several species of Iron-pyrites, Arse- 

 nical-pyrites, Copper-pyrites, several Haloides, Barytes, 

 &c., in beds also by dodecahedral Garnet, octahedral Iron- 

 ore, and several species of Augite-spar. It is not rare in 

 rich silver veins, and is associated with native Silver, and 

 the different ores of that metal. 



4. Yellow Blende principally occurs in fine varieties at 

 Schemnitz in Lower Hungary, and at Kapnik in Transyl- 

 vania ; also at Scharfenberg, Schwarzenberg, and Ritters- 

 griin in Saxony, at Ratieborzitz in Bohemia, at Gumme- 

 rud in Norway, and other places. Brown Blende is found 

 at Freiberg, and other localities in Saxony, in Bohemia, 

 Hungary, and Transylvania, in the Hartz, at Sahla in Swe- 

 den, in great quantities in Derbyshire and Cumberland ; 

 also in Cornwall in England. The radiated variety in parti- 

 cular is found at Przibram ; it is that variety which contains 

 the greatest proportion of cadmium. The chief localities of 

 fibrous Blende are Raibel in Carinthia, Geroldseck in Swa- 

 bia, and Wheal Unity in Cornwall ; of black Blende, Frei- 

 berg, Annaberg, Breitenbrunn, and Schwarzenberg in 

 Saxony, and many places in Bohemia, Hungary, Transyl- 

 vania, Silesia, in the Hartz and other countries. 



5. The application of dodecahedral Garnet-blende for the 

 extraction of zinc, is as yet very limited. 



