CHEMICAL FORMULAS OP MINERALS. 



345 



Kreittonite, (var. of Spinel), 

 Halloysite (161), 

 Heulandite (164), 

 Stilbite (165), 

 Apophyllite (165), 

 Laumontite (166), 

 Natrolite (166), 

 Scolecite (167), 

 Thomsonite (167), 

 Harmotome (168), 

 Analcime (168), 

 Chabazite (169), 

 Prehnite (170), 

 Sillimanite (172), 

 Kyanite (173), 

 Andalusite (174), 

 Staurotide (174), 

 Leucite (175), 

 Orthoclase (176), 

 Albite (177), 

 Labradorite (178), 

 Nepheline (179), 

 Scapolite (180), 

 Meionite (181), 

 Petalite (182), 

 Epidote (182), 

 Allamte (183, 207), 

 Idocrase (184), 

 Garnet (184), 

 Tourmaline (187), 

 A.xinite (190), 

 Iolite (190), 

 Muscovite (191), 

 Biotite (193), 

 Phlog^pite (193), 

 Topaz (194), 

 Beryl (197), 



(2n, Fe) (£l, 3Pe) 



£lSi-f-3fl (in part) 



CaSi+^lSi 3 +5fi: 



CaSi+XlSi 3 +6fi 



Ca, K, Si, fl, F. 



Ca 3 Si 2 -f3&lSi 2 +:2S 



NaSi+3clSi+2a 



CaSi+£lSH-3fi 



R 8 Si+3^1Si-f7fi 



fiaSi+2fclSi a +5fi 



Na8'Si a -|-33clSi 2 + 6fl 



ft 8 Si*+32fcl§i 8 +18fl 



20a 3 Si+33clSi+H 3 Si 



SlSi*.; (partly 3tlSi?) 



£lS if 



A^lSi 1 



SlSi* 



K 3 Si 2 +3£lS> 



(K+A^S'feKSi-fA^lSi 3 



(Na+^l)Si 4 =Na'Si+^lSi 3 



(Ca+£l)Si 3 =CaSi+ aBSi 



(Na-f 3tl)Si3" =Na 2 Si^-2^tl'Si 



(iR s +|Xl)Si^=R 3 Si+^S 8 



(iOa3+fSl)Si=Ga 3 Si+ 2£lSi 



( y&*+$ £l)Si 4 =R 3 Si 4 +4£lSi' 



(&R 3 +f 3l)Si=ft3Si+ 2£l§i 



(iE3+^l)Si=R3Si-{-XlSi 



(f R 3 +f £l)Si=3R 3 Si+ 23fclSi 

 (iE3+iXl)Si=R3g i+ ^isi 



(R 3 , 3tl, B)gi* 

 (R3,S,B)Si 



(iR 3 +f^l)Sit-R3Sit-h3^1Si^ 

 ( T VS 3 + ffS)3i* =R 3 kt+ 1 2R Sit 



(iR 3 +i^l)8.i=R3gi-f^isi 

 (fR 3 +Pl)Si=3R3§i+2Mi 

 3tlSi» with F replacing part of O 

 (iBe4-i£l)Sl2= S-e'S.2+ A1S12 



