DETERMINATION OF MINERALS. 401 



B NOT FORMING A STIFF JELLY WITH ACID ; HYDROUS. 

 a. Blue with cobalt solution (owing to presence of aluminum). 



WAVELLITE, p. 201. H. =3 25-4; G. =2-3-2-4; white to green, 

 brown ; B.B. bluish -green flame after moistening with sulph. acid. 



LAZULITB, p. 199. H.=5'6; G. =3-3-1 ; blue; B.B. green flame, 

 especially after moistening- with sulph. acid ; hydrous. 



TURQUOiS, p. 200. H.=6 ; G. =2 "6-2 85 ; sky-blue, pale green ; 

 B.B. flame green. 



KAOLINITE, p. 310. H. =1-2 ; G. =2*4-2 65 ; white when pure; 

 feel greasy ; B.B. flame not green. 



GIBB3ITE, p. 194. H.=2'5-3-o ; G.=2'3-2'4; white, grayish, green- 

 ish ; B.B. flame not green ; soluble in strong sulph. acid. 



DIASPORE, p. 194. H. =6*5-7 ; G. =3-3-3'5 ; in thin foliated crys- 

 tals, plates or scales ; white, greenish, brownish ; B.B. flame not 

 green ; soluble in sulphuric acid after ignition. 



b. Pale red or pink color, with cobalt solution (owing to presence of 

 magnesium). 



BRUCITE, p. 204. H.=25 ; G. =2-3-2-45; pearly, white, green- 

 ish ; foliaceous or fibrous and flexible ; B.B. after ignition, alkaline. 



c. Not blue or red with cobalt solution. 



OPAL, p. 239. H. =55-6-5; G-19-23; B.B. with soda soluble 



with effervescence. 

 GENTHITE, p. 309. H.=3-4; G.=24; pale green, yellowish; 



B.B. with borax a violet bead, becoming gray in B.F. owing to 



nickel ; decomp. by H CI. 

 CHRYSOCOLLA, p. 142. H.=2-4 ; G.=2 2-24 ; pale bluish-green 



to sky-blue ; B.B. flame emerald-green, and with soda on coal globule 



of copper. 



The micas, chlorites, chloritoid, and serpentine often fuse on their 

 edges with much difficulty. 



C. NOT FORMING A STIFF JELLY ; ANHYDROUS. H. =5 to 9. 



a. Blue color with cobalt solution. 



CORUNDUM, p. 192. H.=9; G.=4; rhombohedral ; blue, white, 



red, grav, brown. 

 CHRYSOBERYL, p. 196. H.=8*5 ; G.=37 ; gray, green, to eme- 

 rald-green. 

 TOPAZ, p. 286. H.=8; G.=3'5; in rhombic prisms with perfect 



basal cleavage, rarely columnar ; white, wine-yellow, and other 



shades. 

 RUBELLITE, p. 283. H.=7'5 ; G.=3 ; in prisms of 3, 6, or 9 sides ; 



rose-red ; reaction for boron. 

 ANDALUSITE, p. 284. H.=7-5; G.=3-2; always in prismatic 



crystals, often tesselated within, I/\I=9S D ; grayish- white to brown. 

 FIBROLITE, p. 285. H. =6-7 ; G.=3"2 ; columnar or fibrous forms 



and prismatic crystals with brilliant diag. cleavage. 



