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Outlines of the Mineralogy and Geology 



ORDER ir. 



'O.YACiniFEEOUS SUBSTA^YCES. 



These are composed of earths united with each other ; some- 



I 



times admitting an acid, alkali, or metallick oxide into their com- 

 position. They are grouped according to the similarity of their 

 chymical composition. 



t-j- Silica nearly or quite pure. 



Species L — Quartz. 



Subspecies I. Common Quartz. 



I 



Variety 1. Limpid Quartz. 



II. Hornstone. 



t| Silica, Jllumineand an Alkali. 



Species II. — Petrosilex. 



m. 



Mica. 



IV.—Schorl. 



t4- Silica, Mumine, Lime and an Mkali, 



V. — Feldspar. 



■ 

 r 



t^ Silica, Jllumine and Lime. 



VI. 



Basalt. 



VII.— Wacke. 



VJIL—Garnet." 

 IX. — Epidote, 



X. 



Prehnite 



t^ Silica, Lime and Water. 



XI. 



Schaalstone. 



I 



Suhspedes I. Chelrasfordifc 



t4 SiUca, Magnesia and Lime. 



XII. 



Tremolite. 



Variety I. Common Tremolite. 



2. Fibrous Tremolite. 



Pirf* 



ib^ 



