DETERMINATION OF MINERALS. 399 



B. SULPHATES or SULPHIDES : Reaction for Sulphur 

 with Soda. 



A. FUSIBLE ; ASSAY ALKALINE AFTER FUSION. 



BARITE, p. 220. H.=2o-35 ; G. =4 3 472 ; trimetric ; white, ywh, 

 gyh, bluish, brown; B.B. decrepitates and fuses ; flame yellow- 

 ish-green ; anhydrous. 



CELESTITE, p. 222. H. =3-3-5; G.=3'9-3-98; trimetric; white, 

 pale blue, rdh ; B. B. fuses ; flame red ; anhydrous. 



ANHYDRITE, p. 211. H.=3-3 5; G.=2-9-3 0; trimetric, with 

 three rectangular and easy cleavages differing but slightly ; white, 

 bluish, gvh, rdh, red; B.B. fuses, flame reddish-yellow. 



GYP8UM; p. 210. H. =1-5-3 ; G. =2 3-2 35; monoclinic, one per- 

 fect, pearly cleavage ; white, gray, but also brown, black from im- 

 purities ; B.B. yields much water, becomes white and crumbles 

 easily. 



B. FUSIBLE ; REACTION FOR IRON. 



COPIAPITE, p. 182. H.=15; G. =2 14 ; yellow ; on coal, becomes 

 magnetic ; hydrous. 

 Hauynite, p. 270, also gives the sulphur reaction with soda. 



C. INFUSIBLE, OR NEARLY SO. 



ALUMINITE, p. 199. H.=l-2 ; G.=166 ; adheres to the tongue ; 



white ; B.B. blue with cobalt solution. Alunite, p. 198, is similar, 



but H.=4, and G.=2 58-2 75. 

 SPHALERITE, p. 154. H.=35-4 ; G. =3 9-4 -2 ; isometric ; light 



to dark resin-yellow ; B.B. on coal, coating of zinc oxide. 



C. ARSENATES : Arsenical fumes on coal. 



SCORODITE, p. 185. H.=3 5~4 ; G. =3-1-3 3 ; trimetric ; leek-green 



to liver-brown ; B.B. fuses easily, flame blue, and with soda gives 



a magnetic bead ; on coal alliaceous fumes ; in H CI. sol. 

 PHARMACOSIDERITE, p. 185. H.=2 5; G. =2-9-3; cubes and 



tetrahedrons ; dark green, bnh, reddish ; B.B. same as for score - 



dite. 

 PHARMACOLITE,p. 214. H.=2-25 ; G. =2-6-2-75 ; wh, gyh, rdh ; 



monoclinic with one eminent cleavage ; B.B. fuses, flame blue ; 



on coal, alliaceous fumes ; after ignition assay alkaline ; in HC1 



sol. 



