400 DETERMINATION OF MINERALS. 



D. SILICATES, PHOSPHATES, OXIDES : SPECIES NOT IN- 

 CLUDED IN THE THREE PRECEDING SUBDIVISIONS. 



I. Streak deep red, yellow, brownish-yellow, green or black. 



A. INFUSIBLE, OR FUSIBLE WITH MUCH DIFFICULTY. 



HEMATITE, p. 1T6. Red to black ; streak red ; B.B. reaction for 

 iron ; magnetic after ignition in R.F. ; anhydrous. 



LIMONITE, p. 181. Brownish and cchre-yellow to black ; streak 

 brownish -yellow ; B.B. gives off water, turns red, becomes mag- 

 netic in R.F. 



TURGITE, p. 182. Brown to black ; streak red ; B.B. gives off 

 water ; decrepitates ; becomes magnetic in R.F. 



FERGUSONITE. p. 202. Brownish black ; infusible. 



ZINCITE, p. 155. Red ; streak orange ; B B. on coal, zinc oxide 

 coating, and coating moistened with cobalt solution, green in R.F. 



B. FUSIBLE WITHOUT MUCH DIFFICULTY. 



WOLFRAMITE, p. 183. Grayish to brownish black ; streak dark 

 reddish brown to black; lustre submetallic ; G =7 1-755. B.B. 

 fuses easily, and becomes magnetic ; reaction for tungsten. 



VIVIANITE, p. 184. Blue to green ito white ; streak bluish- 

 white : G.=25-2'7 ; H. =1 5-2, hydrous ; B.B. fuses easily to mag- 

 netic globule, coloring flame bluish-green. 



TORBERNITE, p. 170. Bright green, square tabular micaceous 

 crystals ; streak paler green ; H.=2-2'5 ; hydrous ; yields a globule 

 of copper with soda. 



SAMARSEITE, p. 202. H.=5 5-6; ©.=5 6-5 8; velvet-black; 

 streak dark reddish brown ; B.B. fuses on the edges. 



LT. Streak grayish or not colored. 



1. INFUSIBLE. 



A. GELATINIZE WITH ACID, FORMING A STIFF JELLY. 



CHRYSOLITE, p. 255. Yellow-green to olive -green, looking like 

 glass ; H. =67 ; G. =33-3 5 ; B.B. reacts for iron, becomes mag- 

 netic ; anhvdrous. 

 CHONDRODITE, p. 281. H.=6-6 5; G. =31-3-25; pale yellow 

 to brown, and reddish -brown ; lustre vitreous to resinous ; B.B. re- 

 action for iron and fluorine ; anhvdrous. 

 ALLOPHANE. p. 29(3. H.=3 ; *G. = 18-1*9 ; always amorphous, 

 never granular in texture; bluish, greenish ; B.B." infus., a blue 

 color with cobalt solution ; hydrous. 



Wi'ltmite, Calamine, Stpiolite, fuse with great difficulty, and are in- 

 cluded under fusible gelatinizing species, p. -102. 



