PHYSIOGRAPHY. 151 



Quartz. 



colors and delineations, as Rock crystal, Amethyst, Rose Quartz, Chry- 

 soprase, several varieties of Calcedony, called Onyx, Sard, Sardonyx, 

 &c., are cut and polished into ring stones, seals, and various other orna- 

 ments. Agate is also used for the same purposes. The most important 

 application, however, is that for the manufacture of glass, and pottery. 

 It is used also as a flux in the melting of several kinds of ores. Its use 

 in gun locks is also well known. Sandstones yield various applications 

 for architectural and other purposes, as the construction of melting fur- 

 naces, mill-stones, &c. Sand, with slaked lime, forms mortar. 



QuiNCYTE. 



Massive ; composition granular. 

 Color carmine-red. 



1. It loses its color by heat, and is with difficulty fusible before the 

 blow-pipe. 



2. Analysis. 

 By BERTHIER. 



Silica 54-00 



Magnesia 19-00 



Protoxide of iron 8-00 



Water 17-00 



3. It is found in the fresh water limestone of Mehun and Quincy, in 

 the department of Cher. 



4. The description is too imperfect, to lead to any opinion of its spe- 

 cific character. 



RADIOLITE. 



Massive : composition columnar, particles of composition radia- 

 ting : compact. Cleavage, distinct in one direction. 

 Lustre silky, glistening. Color white. 

 Hardness, above Fluor.' Sp. gr. = 2-275 . . . 2-286. 



1. Analysis. 

 By HUJTXEFIELD. 



Silica 41-88 



Alumina 23-79 



Soda 14-07 



Potash 1-01 



Water 1-00 



Oxide of iron 0-91 



Carbonate of lime 2-50 



Gangue 5-50 



2. It is found at Eckefiord in Norway. 



