4:04 DETERMINATION OF MINERALS. 



or affording very little water; B.B. fuse with difficulty on thin 

 edges, excepting lepidonielane which fuses rather more easily. 



MARGARODITE, DAMOURITE, p. 813. 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. 



FENNINITE. RIPIDOLITE, FROCHLORITE, p. 318. Usually 

 bright or deep green, blackjsh-green, reddish, rarely white ; folia 

 tough, inelastic; B.B. diff. fus., reaction for iron and yield much 

 water ; partiallr decomposed bv acids. 



VERMICULITE, JEFFERISITE. p. 317. Brown, yellowish-brown, 

 green ; exfoliate remarkably ; yield much water. 



MARGARITE, p. 319. H.=3 5-4o I highest on edges); G.=2 99; 

 white, ywh, rdh ; folia somewhat brittle ; B.B. fuses on thin edges ; 

 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, 

 yields usually traces of water ; reddish with cobalt solution. 



PYROPHYLLITE, p. 306. Similar to talc ; but B.B. exfoliates 

 remarkably ; blue with cobalt solution. 



FAHLUNITE, p. 314, has often a more or less distinct micaceous 

 structure. 

 Autunite, p. 1T0, has a mica-like basal cleavage ; but it occurs 



in small square tables of a bright yellow color. Biallage, p. 246, 



has a structure nearly micaceous. Serpentine is sometimes nearly 



micaceous, but the folia are not easily separable and are brittle. 



Ghloritoid 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. XO REACTION FOE PHOSPHORUS, OR BORON. 



t Hardness, with, the exception of a variety of serpentine, 1 to 3 '•> 

 lustre not at all vitreous, 



CHLORITES, p. 318. H.=2-2 5. Here fall the massive granular 

 chlorites, olive-green to black in color, of the species penninite, ri- 

 pidolite, procldorite ; B.B. reaction for iron, fuses with difficulty; 

 yields much water. 



VERMICULITE, p. 317. H. =1-1-5. Granular massive forms of 

 vermiculite. 



TALC, p. 304. H. =1-1 o. Here falls steatite (soapstone) or massive 

 talc, of white to grayish green and dark green color, granular to 

 cryptocrystalline in texture. B.B. fuses with great difficulty, and 

 yields onlv traces of water ; no reaction for iron, or onlv 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. 



