402 DETERMINATION OF MINERALS. 
CYANITH, p. 286. H.—5-7 (greatest on extremities of crystals) ; 
G.—3°'6 ; in long or short prismatic crystallizations, often bladed 
prisms ; pale blue to white and gray. . 
LEUCITE, p. 271. H.=5'5-6 ; G.=2'5 ; white, gyh ; often in trapezo- 
hedral crystals. 
b. Not giving a blue or reddish color with cobalt solution; H.= 
8 to 5. ‘ 
SPINEL, p. 194. H.—8; G.=8°5-4-1; in octahedrons of red, green- 
ish, gray, black colors. Gahmnite is similar, but with borax on coal, 
gives reaction for zinc. 
BERYL, p. 252. H.=7:5-8; G.=2°6-2°7; always in hexagonal 
prisms ; pale bluish and yellowish green, to emerald-green, also 
resin yellow and white, no distinct cleavage. 
ZIRCON, p. 259. H.=7°5 ; G.=4-4°75 ; dimetric, and often in square 
prisms ; lustre adamantine ; brown, gray. 
STAUROLITH, p. 291. H.=7; G.—34-3°8; in prisms of i23°, 
and often in cruciform twins; no distinct cleavage ; brown, black, 
gray. 
QUARTZ, p. 233.. H.=7; G.=2°6; often in hexagonal crystals 
with pyramidal terminations; of various shades of color. OPAL, 
p. 289, is in part anhydrous. 
MONAZITEH, p. 203. H.=5-5'5; G.—4°9-5°3; in small brown im- 
bedded monoclinic crystals, with perfect basal cleavage ; B.B. flame 
bluish-green when moistened with sulph. acid. 
RUTILE, p. 162. H.=—6-65; G.=—4:15-4:25; dimetric; reddish- 
- brown to brownish-red, green, black ; B.B. reaction for titanium. 
BROOKITE and OCTAHEDRITE, p. 163, are similar, except in crystal- 
line forms, and G. in brookite 4°0-4'25, in octahedrite 3°8-3°95. 
PEROF'SKITE, p. 163. H.=55; G.=4-4:1; yellowish, brown; 
black ; cubic and octahedral forms ; B.B. reaction for titanic acid. 
ENSTATITE, p. 244. H.—5°5 ; G.=8:1-3°'3 ; in prismatic and fibrous 
forms with ZA J=88’ 16’, also foliated ; whitish, grayish, brown. 
Anthophyllite is similar, but JA /=125°, and it fuses on the edges 
with great difficulty. 
folite, apatite, scheelite, euclase, fuse with much difficulty, and 
euclase gives some water in closed tube when highly ignited. 
2. FUSIBLE WITH LITTLE OR MUCH DIFFICULTY. 
A. Gelatinize and afford a Stiff Jelly. 
a. Hydrous; fuse easily. 
DATOLITE, p. 289. H.=5-5°5 ; G.—2°8-3; white, greenish, yel- 
lowish ; crystals glassy, stout, sometimes massive and porcellanous, 
never fibrous ; B.B. fuses easily, reaction for boron. | 
NATROLITE, p. 299. H.=—5-5°5 ; G.=2°3-2:.4; in slender rhombie 
prisms, and divergent columnar ; white, ywh, rdh, red; B.B. fuses 
very easily. 
SCOLECITE, p. 299. H.—5-5'5; G.—2°16-2°4; cryst. much like 
