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, bnh red, gyh; 
streak scarlet. 
AMALGAM, p. 117. H.=3-3°5; G.=18-14 ; 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.=55; G.=4:3-4°5; isometric, often in 
octahedrons, massive ; submetallic ; bnh iron-black, streak brown ; 
B.B. on coal becomes magnetic; with borax, a kead which is 
emerald-green on cooling. 
CROCOITEH, p. 150. H.—25-8; 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. Phenicochroite 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.—5:5; G.=6-63; 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. 
LINN ITE, 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 UNMETALLIC. 
ERYTHRITBE, p. 167. H.=15-25; G.=295; monoclinic, one 
highly perfect cleavage, also earthy ; rose-red, peach-blossom red, 
streak reddish ; B.B. fuses easily ; yields water. 
