166 PHYSIOGRAPHY. 



Rionite. 



will amount to 99-5. It is, therefore, a bi-seleniuret of zinc united to a 

 proto-sulphuret of mercury ; the latter giving the grey color to the min- 

 eral. The red mineral is regarded as a bi-seleniuret of zinc, the mer- 

 cury being in the state of a bi-sulphuret, which communicates the red 

 color. 



3. It is found at Calebras, near the mining district of El Doctor, in 

 limestone, overlying^ the red sandstone, and is accompanied by Native 

 Quicksilver. 



4. A fuller examination of the red and grey varieties, may show that 

 they form distinct species. 



ROSELITE. 



Primary form. Right rhombic prism. M on M =132 48'. 

 Secondary form. 



Fig. 384. 



a on a over d = 45 0' 



Cleavage perfect parallel to d. Surface M rough and hollow- 

 ed out in the middle. 



Lustre vitreous. Color deep rose-red. Streak white. Trans- 

 lucent. 



Hardness =3-0. 



1. Before the blow-pipe, it gives off water and becomes black. It im- 

 parts a blue color to borax and salt of phosphorus ; and is entirely so- 

 luble in muriatic acid. According to CHILDREN, it contains water, ox- 

 ide of cobalt, lime, arsenic acid and magnesia. 



2. It occurs at Sclmeeberg in Saxony, disposed on Quartz, and was 

 formerly considered as a variety of Cobalt-Bloom. 



3. It is nearly related to Pharmacolite. 



RUBELLAN. 



In six-sided prisms, whose angles are not known. 

 Cleavage perfect in one direction. 



