76 
CONTRIBUTIONS TO MINERALOGY. 
[BULL. 262. 
Adamite. 
The analcite upon which the following experiments were made was 
well crystallized material from Table Mountain, near Golden, Colo. 
Three silver derivatives were prepared as follows: 
A. Ammonium analcite was heated in a sealed tube with four times 
its weight of dry silver nitrate for 4 hours at 250°-290° C, then 
leached with boiling water and the residue dried on the water bath. 
B. The natural analcite was heated in a sealed tube with four times 
its weight of dry silver nitrate for 4 hours at 250°-290° C, then 
leached and the residue dried on the water bath. 
C. Same as B, but heated 6 instead of 4 hours. 
D. Analysis of the analcite upon which the experiments were made. 
Analysis gave the results shown below: 
Si0 2 . . 
Al A - 
Ag 2 . 
CaO .. 
Na 2 . 
H 2 0- 
H 2 0+ 
NH 3 .. 
42.69 
18.22 
32. 01 
68 
In leach water: 
Na.,0. 
6.09 
.69 
100. 38 
60 
41.31 
16.44 
37. 45 
.85 
4.29 
100. 34 
13. 13 
40.08 
16.29 
36. 91 
si 
5. 86 
99. 95 
12.57 
55. 72 
23. 06 
.17; 
12.46 
.13 
8. 26 J 
99. 80 
The products were all perfectly white, showing that no free silvei 
oxide contaminated the residue. Under the microscope a small amounl 
of the material showed double refraction, but the larger portion of |i 
was isotropic like the original mineral. 
Residue A was boiled for 15 minutes with a 5 per cent solution o 
sodium carbonate, and only a trace of silica passed into solution. Wit! 
nitric acid the silver analcite gives sandy silica, and does not gelatinizi 
on evaporation. 
A portion of residue B was heated on the water bath for 2£ hour 
with a 10 per cent solution of sodium hyposulphite and afterward ;[ 
washed with water. In the residue 9.45 per cent of Na.,0 was found 
showing that the silver salt had been converted back into the sodim ii 
compound, though not completely, the theoretical amount of Na 2 ( ( | 
required being 14.1 per cent. Whether a hydrated salt had been forme 
was not determined. After treatment in a similar manner with potai 
shim c} T anide 10.04 per cent of K.,() was found in the residue. 
