404 DETERMINATION OF MINERALS. 
or affording very little water; B.B. fuse with difficulty on thin 
edges, excepting lepidomelane which fuses rather more easily. 
MARGARODITS, DAMOURITEH, p. 3138. Much like common 
mica, but more pearly and greasy to the feel, folia not elastic ; giv- 
ing a little water in the closed tube ; color usually whitish. 
PENNINITE, RIPIDOLITE, PROCHLORITE, p. 518. Usualiy 
bright or deep green, blackish-greer, reddish, rarely white ; folia 
tough, inelastic ; B.B. diff. fus., reaction for iron and yield much 
water ; partially decomposed by acids. 
VERMICULITH, JEFFERISITE, p. 317. Brown, yellowish-brown, 
green ; exfoliate remarkably ; yield much water. 
MARGARITE, p. 319. H.=3°5-4'5 (highest on edges) ; G.=2°99; 
white, ywh, rdh ; folia somewhat brittle ; B.B. fuses on thin edg<s ; 
yields a little water. 
TALC, p. 304. H.=—1-1:°5; G.=2°5-2°8; pearly and very greasy to 
the touch; white, pale green, gray ; B.B. very difficultly fusible, 
vields usually traces of water ; reddish with cobalt solution. 
PYROPHYLLITE, p. 306. Similar to tale; but B.B. exfoliates 
remarkably ; blue with cobalt solution. 
FAHLUNITE, p. 314, has often a more or less distinct micaceous 
structure. 
Autunite, p. 170, has a mica-like basal cleavage ; but it occurs 
in small square tables of a bright yellow color. Diéallage, p. 246, 
has a structure nearly micaceous. Serpentine is sometimes nearly 
micaceous, but the folia are not easily separable and are brittle. 
Chioritoid has a perfect basal cleavage, but folia very brittle, and - 
cleavage less easily obtained than in the preceding ; and moreover the 
mineral is infusible. 
2. STRUCTURE NOT MICACEOUS. 
a. Hydrous. 
a. NO REACTION FOR PHOSPHORUS, OR BORON. 
+ Hardness, with the exception of a variety of serpentine, 1to3; 
lustre not at all vitreous, 
CHLORITBES, p. 318. H.=2-25. Here fall the massive granular 
chlorites, olive-green to black in color, of the species penninite, ri- 
pidolite, prochlorite ; B.B. reaction for iron, fuses with difficuity ; 
yields much water. 
VERMICULITE, p. 317. H.=1-1°5. Granular massive forms of 
vermiculite. 
TALC, p. 304. H.=1-1°5. Here falls steatite (soapstone) or massive 
tale, of white to grayish green and dark green color, granular to 
cryptocrystalline in texture. B.B. fuses with great difficulty, and 
yields only traces of water ; no reaction for iron, or only slight. 
PYROPHYLLITE, p. 306. Grayish white, massive or slaty; B.B. 
like the crystallized, p. 403, in its difficult fusibility and little water 
yielded, but does not exfoliate. 
SERPENTINE, p. 307. H.=2°5-4; G.=2:36-2°55; olive-green ; 
ywh green; blackish green, white; B.B. fuses with difficulty on 
thin edges ; yields much water. 
