82 CONTRIBUTIONS TO MINERALOGY. 
C. Analysis of the original chabazite: 
[BULL. 262. 
! A. 
Si0 2 .. 
AUV 
Fe 2 3 . 
Ag,0 . 
L fe2 
CaO . 
Na 2 
K 2 . 
H 2 0- 
H 2 
In the leach water: 
A1 2 3 
CaO 
Na,0 
38.84 
11.02 
84. 95 
11.89 
28. 95 
39. 63 
40 
2.38 
4.40 
6.64 
100.29 
none 
7.75 
1.98 S 
50. 78 
17. 18 
.40 
7.S4 
1.28 
.73 
5. 22 
16.63 
100.06' 
This preparation was light in color, showing that no appreciable 1 
amount of free silver oxide could have been present. It was decomiii 
posed easily by nitric acid, giving sand}^ silica. 
The microscopic examination showed the material to be entirely 
crystalline and uniaxial. 
In this, and as will be shown later in the thallium derivatives also 
important amounts of N 2 5 have been retained. This is not duo t< I 
incomplete washing, but the nitrate is firmly held within the molecule! 
This same mineral gave, with ammonium chloride, a compound con | 
taming chlorine. What the presence of these small amounts of tb j 
acid radicles ma}^ mean is not known, but in the following reduction if 
N 2 5 will be considered as combined directly with silver or thalliun ;j 
the proper amount will be subtracted from the analysis. 
Deducting water below 100° and also silver nitrate, analysis 
becomes: 
Residue H. 
Si0 2 . 
A1 2 3 
Ag 2 
Na 2 ( ) 
H,0 . 
45.30 
15.41 
33. 07 
. 52 
,5.70 
100.00 
Moleeula 
ratioi 
100(; 
20 lj 
19 11 
1 
-IL ; 
