268 PHYSIOGRAPHY. 



Horn Quicksilver Horn Silver. 



Lustre adamantine. Color yellowish grey or ash-grey, 

 also yellowish and greyish white. Streak white. Trans- 

 lucent, sometimes only on the edges. 



Sectile. Hardness =1-0. . .2-0. Sp.gr. =6*482. 



Compound Varieties* Crystalline coats, probably form- 

 ed originally upon globules of fluid mercury : composition 

 not observable. Massive : composition granular. 



1. Before the blow-pipe, upon charcoal, it is entirely volatilized, if 

 pure. It is not soluble in water. 



2. Analysis. 



Oxide of mercury -. 88-43 



Muriatic acid 11-52 



3. This rare mineral occurs in secondary rocks, along with Cinnabar 

 and ochry v^rieties^of Iron-Ore. 



4. Its chief locality is Moschellandsberg in Deuxponts, but it also oc- 

 curs at Idria in Carniola, and Almaden in Spain. At Horzowitz in Bohe- 

 mia, it has been found with Cinnabar in veins, traversing a bed of Iron-Ore. 



HORN SILVER. Hexahedral Pea rl-Kerate. 



MOHS. 



Primary form. Cube. 

 Secondary forms. 



1. Fig. 252. 



2. 



Octahedron. 



Siberia. 



Cornwall, England. 

 3. Fig. 253. 



X d 



4. 

 Rhombic dodecahedron* 



Siberia- 



Johanngeorgenstadt 



