40G DETERMINATION OF MINERALS. 



PETALITE, p. 248. H.=6-6 5; G.=2'4-2o; white, gray, rd]i, 

 gnli ; B.B. becomes glassv and fuses onlv on the edges. 



HJ3BRONITE, AMBLYGONITE, p. 199. H.=6 ; G.=3-31 ; moun- 

 tain green, gyh, white, bnh ; B.B. fuses very easily, reaction for 

 fluorine. 



TRIPHYLITE, p. 190. H.=5; G. =3 5-36; greenish gray, bluish, 

 often bnh black externally ; B.B. fuses very easily, globule mag- 

 netic ; with soda, manganese reaction. 



LEPIEOLITE, p. 268. H =2 5-4 ; G. =2-8-3 ; micaceous, also scaly- 

 granular ; rose-red, pale violet, white, gyh ; B.B. fuses easily; 

 after fusion gelat. with H CI. Some biotite, p. 266, gives the litliia 

 reaction. 



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



TOURMALINE, p. 282. H.=7 ; G. =2 9-3 -3 ; rhombohedral, prisms 

 with 3, 6, 9 sides, no longitudinal or other distinct cleavage ; black, 

 blue black, green, red, rarely white ; lustre of dark var. resinous ; 

 B. B. fusion easy for dark var. and diff . for light. 



AXINITE, p. 204. H. =6-5-7 ; G. = 3 27 ; triclinic, sharp-edged, glassy 

 crystals ; rich brown to pale brown and grayish ; B.B. fuses readily ; 

 with borax violet bead. 



BORACITE. p. 206. H. =7 ; G. =2 97 ; isometric ; white, gyh, gnh ; 

 lustre vitreous ; fuses easily, coloring flame green. 



Danburite, p. 264, is another boron silicate. 



y. B.B. reaction for titanium. 



TITANITE, p. 290. H. =5-5-5 ; G.=3*4-3-56 ; monoclinic ; usually 

 in thin sharp-edged crystals ; brown, ywh, pale green, black ; 

 lustre usually subresinous ; B.B. fuses with intumescence. 



8. Reaction for fluorine or phosphorus. 



CRYOLITE, p. 197. H.=2"5 ; G.=29-3 ; white, rdh, bnh ; fuses in 

 the flame of a candle ; soluble in sulph. acid which drives off hydro- 

 gen fluoride, a gas that corrodes glass. 

 FLUORITE, p. 208. H. =4 ; G.=3-3'25; isometric, with perfect 

 octahedral cleavage, and massive ; white, wine-yellow, green, pur- 

 ple, rose-red, and other bright tints ; phosphoresces ; when heated, 

 decrepitates ; B.B. fuses, coloring the flame red ; after ignition, 

 alkaline. 



Ltpidolite (p. 268), Ambhjgonite (p. 199), also give a fluorine re- 

 action. 



APATITE, p. 212. H. =1*5-5; G. =2 '9-3 '25 ; often in hexagonal 

 prisms ; pale green, bluish, yellow, rdh, bnh, pale violet, white ; 

 B.B. fuses with difficulty, moistened with sulph. acid and heated, 

 flame bluish green from presence of phosphorus ; sometimes reaction 

 for fluorine. 



e. Reaction for iron. 



GARNET, p. 256. H. =65-7 '5 ; G. =3-15-43 ; isometric, usually in 

 dodecahedrons and trapezohedrons, also massive, never fibrous or 

 columnar ; red, bnh red, black, cinnamon red, pale green, to emerald- 



