DETERMINATION OF MINERALS. 387 
C. ARSENATES : on coal arsenical fumes. 
D. SILICATES, PHOSPHATES, OXIDES: 
Species not included in the preceding subdivisions. 
I. STREAK DEEP RED, YELLOW, BROWNISH-YELLOW, GREEN, OR 
BLACK. 
A. Infusible, or fusible with difficulty. 
B. Fusible without much difficulty. 
Il. 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. 
b. Reddish or pink color with cobalt solution. 
c. Not blue or red with cobalt solution. 
. Not forming a stiff jelly ; anhydrous. 
a. Blue color with cobalt solution. 
6. Not blue-or reddish color with cobalt solution. 
a) 
2. Fusible with more or less difficulty. 
A. Gelatinize and form a stiff jelly. 
a. Hydrous; fuse easily. 
6. Hydrous ; fuse with much difficulty. 
c. Anhydrous. 
a. No reaction for sulphur ; no coating on coal. 
fs. Reaction for sulphur with soda. 
B. Not gelatinizing. 
1. Structure eminently micaceous ; folia tough, pearly, 
and H. of surface of folia not over 8°5 ; anhydrous 
or hydrous. 
2. Structure not eminently micaceous. 
a. Hydrous. 
«. No reaction for phosphorus, or boron. 
+. H.=1 to 8; lustre not at all vitreous. 
+}. H.=35-6°5; lustre of cleavage sur- 
face sometimes pearly ; elsewhere vi- 
treous. 
fs. Reaction for phosphorus or boron. 
6. Anhydrous. 
«a. B.B. lithium-red flame. 
. B.B. boron reaction (green flame). 
. B.B. reaction for titanium. 
B.B. reaction for fluorine or phosphorus. 
B.B. reaction for iron. 
. B.B. no reaction for iron: not of the pre- 
ceding subdivisions. 
UO SN) eS 
