678 MINERALOGY 



ft. Yields a fluorine reaction. 



Fluocerite, (Ca.La.Di) 2 OF 4 .OH ; Reddish yellow ; Cl. 

 two directions; H. 4; G. 5.80; Massive; III. 



Yttrocerite, (Y.Er.Ce)F 3 .5 CaF 2 .H 2 ; Vtolet, gray, 

 brown, white; Greasy; H. 2.5-3; G. 3.45; Mas- 

 sive. 



y. Ignited with cobalt solution becomes flesh-pink 

 (magnesium). 



DEWEYLITE, H 4 Mg 4 (SiO 4 ) 3 .4 H 2 O ; Yellow to apple- 

 green ; Resinous ; H. 3-4 ; G. 2.40 ; Amorphous. 



Sepiolite, H 4 Mg 2 Si 3 Oio ; White to grayish white ; Dull ; 

 H. 2-2.5 ; G. 2.0 ; Compact. 



Usually too dark in color to show pink with cobalt 

 solution. 



SERPENTINE, H 4 (Mg.Fe) 3 Si 2 O 9 ; Olive, blackish, or 

 yellowish green, white; Greasy; H. 2.5-6; G. 2.56; 

 Massive ; p. 498. 

 6. Gelatinizes with HC1. 



ALLOPHANE, Al 2 SiO 6 .H 2 0; White, yellow, green, 



blue; H. 3; G. 1.88; Amorphous, p. 502. 

 c. Insoluble in HG1. 



. Micaceous. 



CLINOCHLORE, H 8 Mg 5 Al 2 Si 3 Oi8 ; Green of various 

 shades ; H. 2-2.5 ; G. 2.75 ; V ; p. 497. 



Clintonite, H 3 (Mg.Ca) 5 Al 5 Si 2 O8; Reddish brown, cop- 

 per-red; Pearly; H. 4-5 ; G. 2.87; V. 



Xanthophyllite, Hs(Mg.Ca)i4Ali 6 Si 5 O5 2 ; Light green ; H. 

 4-5 ; G. 3.09 ; V. 



Prochlorite, H^Fe.Mg^sAlnSiiuOgo?; Green to black- 

 ish green ; H. 1-2 ; G. 2.87 ; V. 



/8. Becomes blue with cobalt solution. 



PYROPHYLLITE, H 2 Al 2 (SiO 3 ) 4 ; White, apple-green, 

 gray, brown; Pearly; H. 1-2; G. 2.85; Foliated, 

 compact ; p. 502. 



KAOLINITE, H 4 Al 2 Si 2 9 ; White; Pearly, dull; Cl. 

 basal; H. 2-2.5; G. 2.60; V; p. 501. 



GIBBSITE, A1(OH) 3 ; White; Pearly, dull ; Cl. basal; 

 H, 2.5-3.5; G. 2.35; V; p. 365. 



BAUXITE, A1 2 O(OH) 4 ; White, gray, yellow, red; Dull, 

 earthy; G. 2.55; Massive, clay-like; p. 366. 



y. Yields a sulphur reaction when fused with soda. 



