392 DETERMINATION OF MINERALS. 



B. Yield drops of mercury in closed tube with or 



without soda. 



COMPOUNDS OF MERCURY. 

 CINNABAR, p. 128. H.=2-2 5 ; G. =8-9 ; bright red, trail red, gyh ; 



g-j-ppolr qpa *p] pf 



AMALGAM, p. 117. H. =3-3-5 ; G. =13-14 ; silver - white ; yields 

 silver B.B. on coal. 



Spaniolite, p. 136, a variety of tetrahedrite, yields mercury. 



C. No malleable globule ; decisive reaction with borax 



or salt of phosphorus for chromium, cobalt, or 



manganese. 



1. COMPOUNDS OF CHROMIUM. 



Give with, borax an emerald-green bead in both flames. 



CHROMITE, p. 180. H.=5*5 ; G.=4*3-4*5; isometric, often in 

 octahedrons, massive ; subnietallic ; bnh iron-black, streak brown ; 

 B.B. on coal becomes magnetic; with borax, a bead which is 

 emerald-green on cooling. 



CROCOITE, p. 150. H.=2 5-3; G. =5*9-6 '1; bright red, streak 

 orange ; B.B. fuses very easily, on coal globule of lead, and with 

 salt of phosphorus emerald-green bead. Phcenicochroite and Vauque- 

 linite are other lead chromates. 



2. COMPOUNDS OF COBALT. 



Give a blue color with borax after, if not before/ roasting. 

 [When much nickel or iron is present the blue color is not ob- 

 tained ; and species or varieties of this kind are not here included.] 



1. LUSTRE METALLIC. 



COBALTITE, p. 165. H.— 55; G. =8-6*8; isometric and pyrito- 

 hedral ; rdh silver- white, streak grayish -black ; B.B. on coal sulph. 

 and arsen. fumes, and a magnetic globule. 



SMALTITE, p. 165. H. =5*5-6; G.=6*4-72; tin- white, streak 

 gyh black : B. B. on coal alliaceous fumes ; most varieties fail to give 

 the blue color immediately with borax, because of the iron and 

 nickel present. 



LINNiEITE, p. 164. H.=5*5 ; G. =4-8-5; isometric; pale steel- 

 gray, copper-red tarnish, streak bkh gray. B.B. on coal sulph. 

 fumes. 



2. LUSTRE U"NMETALLIC. 



ERYTHRITE, p. 167. H.=l*5-2*5 ; G.=2 95; monoclinic, one 

 highly perfect cleavage, also earthy ; rose-red, peach-blossom red, 

 streak reddish ; B.B. fuses easily ; yields water. 



