Clarke and Steiger — Action of Ammonium Chloride. 31 



Si0 



Analysis 

 50'78 



Al 



17-18 



"'""2 3 



Fe 0, 



-40 



MgO 



CaO 



Na 2 



KO 



'04 



7-84 



1-28 



-73 



2 



HO 



21-85 



Fractional water. 



At 100° 5-22 



" 180° 5-70 



" 250° 3-92 



" 350° 2-36 



Low redness 4-51 



Full redness .'13 



Over blast -01 



21-85 



100-10 



The unignited mineral, upon boiling with sodium carbonate, 

 gave 0*86 per cent of soluble silica. After ignition only 0'53 

 per cent was soluble. Here again no silica is liberated by cal- 

 cination, and metasilicate formulae may be disregarded. 



Two samples of the ammonium chloride derivative were 

 prepared, which after thorough washing were dried at 40° to 

 50°. As in the case of stilbite, small quantities of chlorine 

 appear in the compound, not removable by washing. The 

 amount of change effected is also somewhat less than with 

 stilbite, and about the same as with heulandite. The analyses 

 of the two samples are subjoined, with the remaining alkali all 

 reckoned as soda. 



A B 



Si0 2 55-88 56-09 



A1 2 3 19-15 19-49 



CaO 2-25 2-01 



Na 2 0(K 2 0) -35 -24 



NH 3 .. 4-64 4-83 



H 2 16-57 16-01 



CI -95 1-35 



99-79 100-02 



Less O -21 -30 



99-58 



99-72 



In B, 1*50 per cent of soluble silica was found. After 

 ignition, this was reduced to 112 per cent. No liberation of 

 silica accompanies the splitting off of water and ammonia. 



Upon studying the molecular ratios for chabazite and its 

 derivative, relations appear precisely like those found for stil- 

 bite and heulandite. For chabazite itself, rejecting water and 

 the 0'86 per cent of soluble silica, we have 



R' Ca, 



^340^832 2344 , 



or, consolidating soda with lime, 



Ca„.Al la (Si,OJ, M (SiO.) M . 



