142 DESCRIPTIONS OF MINERALS. 



Composition. CuJL0 4 Si = Silica 38-1, copper oxide 50*4, 

 water 1] -5 = 100. B. B. with soda on charcoal yields copper, 

 and this, with its hardness, distinguishes it from, the spe- 

 cies it resembles. 



Obs. From the Khirgeez Steppes of Siberia. 



Chrysocolla. — Hydrous Copper Silicate. 



Usually as incrustations ; botryoidal and massive. Also 

 m thin seams and stains ; no fibrous or granular structure 

 apparent, nor any appearance of crystallization. 



Color bright green, bluish green. Lustre of surface of 

 incrustations smoothly shining ; also earthy. Translucent 

 to opaque. H.=2-4. G. =2-2-4. 



Composition. 0uO 3 Si + 2 aq= Silica 34-2, copper oxide 

 45:3, water 20-5 = 100. 





SIBERIAN. 





NEW JERSE 



T. 





yon Kobell. 



Bert hi er. 



Bow en. 



Beck. 



Oxide of copper 



.. 40-0 



55'1 



... 45.2 



... 42-6 



Silica 



. . . 36'5 



354 



... 373 



... 17-0 



... 40-0 



Water 



. . 20-2 .... 



"7. 28-5 



. . . lo'O 



Carbonic acid. . . 



... 2-1 







. — 



. . . — 



Oxide of iron. .. 



. . . 1-0 .... 











... 1-4 



The mineral varies much in the proportion of its consti- 

 tuents, as it is not crystallized. 



B.B. it blackens in the inner flame, and yields water 

 without melting. With soda on charcoal yields a globule 

 of copper. 



Biff. Distinguished from green malachite as stated under 

 that species. 



Obs. Accompanies other copper ores in Cornwall, Hun- 

 gary, the Tyrol, Siberia, Thuringia, etc. In Chili it is 

 abundant at the various mines. In Wisconsin and Missouri 

 it is so abundant as to be worked for copper. It was for- 

 merly taken for green malachite. It also occurs at the Som- 

 erville and Schuyler's mines, X. J., at Morgantown, Penn., 

 and Woleottville, Conn. 



This ore in the pure state affords 30 per cent, of copper ; 

 but as it occurs in the rock will hardly yield one-third this 

 amount. Still, when abundant, as it 'appears to be in the 

 Mississippi Valley, it is a valuable ore. 



Genera' Remarks. — The most valuable sources of copper for the 

 arts are native copper, clialcopyrite or "yellow copper ore," chalcoc'te 

 or "copper glance," bornite or " variegated copper ore," malachite 



