DETERMINATION OF MINERALS. 387 



C. ARSEXATES : on coal arsenical fnmes. 



D. SILICATES, PHOSPHATES, OXIDES : 



Species not included in the preceding subdivisions. 



Z. STREAK DEEP RED, YELLOW, BROWNISH- YELLOW, GREEN, OE 

 BLACK. 



A. Infusible, or fusible with difficulty. 



B. Fusible without much difficulty. 



H. STREAK GRAYISH OR NOT COLORED. 

 1. Infusible. 



A. Gelatinize with acid, forming a stiff jelly. 



B. Not forming a stiff jelly ; hydrous. 



a. Blue color with cobalt solution. 



5. Reddish or pink color with cobalt solution. 



c. Xot blue or red with cobalt solution. 



C. Xot forming a stiff jelly ; anhydrous. 



a. Blue color with cobalt solution. 



b. Xot blue or reddish color with cobalt solution. 



2. Fusible with more or less difficulty. 



A. Gelatinize and form a stiff jelly. 



a. Hydrous ; fuse easily. 



b. Hydrous ; fuse with much difficulty. 



c. Anhydrous. 



a. Xo reaction for sulphur ; no coating on coal. 

 (i. Reaction for sulphur with soda. 



B. Xot gelatinizing. 



1. Structure eminently micaceous ; folia tough, pearly, 



and H. of surface of folia not over 3*5 ; anhydrous 

 or hydrous. 



2. Structure not eminently micaceous. 



a. Hydrous. 



a. Xo reaction for phosphorus, or boron. 



f. H. =1 to 3 ; lustre not at all vitreous, 

 ff. H. =3'5-6'5; lustre of cleavage sur- 

 face sometimes pearly ; elsewhere vi- 

 treous. 

 /3. Reaction for phosphorus or boron. 



b. Anhydrous. 



a. B.B. lithium -red flame. 

 fi. B.B. boron reaction (green flame). 

 y. B.B. reaction for titanium. 

 6". B.B. reaction for fluorine or phosphorus. 

 e. B.B. reaction for iron. 



%. B.B. no roac -ion for iron : not of the pre- 

 ceding subdivisions. 



