PHYSIOGRAPHY. 17 



Liroconite. 



Secondary form. 



Fig. 281. 



Pon/' 179 22') 



MonP 133 30 \ PHILLIPS. 



I on I 178 10 ) 



Cleavage, parallel with the primary planes, but effected 

 with much difficulty. Fracture imperfectly conchoidal, un- 

 even. 



Lustre vitreous, inclining to resinous. Color sky-blue 

 . . . verdigris-green. Streak corresponding to the color, 

 very pale. Semi-transparent . . . translucent. 



Nearly sectile. Hardness = 2-0 ... 2-5. Sp. gr. = 

 2-926. 



Compound Varieties. Massive; composition granu- 

 lar, sometimes very distinct, but altogether rare. 



1. Before the blow-pipe, it loses color and transparency, emits fumes 

 of arsenic, and is changed into a friable scoria, containing some white, 

 metallic globules. With borax, it yields a green globule, and is partly 

 reduced. In nitric acid, it is soluble without effervescence. 

 2.'" Analysis. 



fBy CHENEVIX. 

 Oxide of copper 49-00 



Arsenic acid ...... 14-00 



Water 35-00 



3. Lenticular Copper-Ore occurs in copper veins, along with various 

 other ores of copper ; also with Limonite, Quartz and Iron Pyrites. 



4. It has been found only in some of the copper mines, near Redruth 

 in Cornwall, and in minute crystals at Herrengrund in Hungary. 



LlTHOMARGE. 



A pure, white, adhesive clay, from the decomposition of one or 

 more species. That from Rochlitz in Saxony, consists, according 

 to KLAPROTH, of 



Silica .--... 45-25 



Alumina 36-50 



Wat3r 14-00 



Oxide of iron 2-75 



2* 



