138 
ANALYSES OF ROCKS, U. S. GEOLOGICAL SURVEY. 
[BULL. 1G8. 
E. Altered rhyolite, De Lamar mine, Silver City, contains quartz, 
sericite, pyrite, apatite, and rutile, with some undeterminable mag- 
nesian mineral. Analysis by H. N. Stokes, record No. 1731. 
F. Altered rhyolite, De Lamar mine. Contains sericite, quartz, 
kaolinite, and pyrite. Sp. gr., 2.655, 23°. 
G. Altered rhyolite, De Lamar mine. Contains quartz, sericite, 
kaolinite, and pyrite. Sp. gr., 2.576, 24°. 
H. Diabasic basalt, Trade Dollar mine, Silver City. Contains labra- 
dorite, augite, chlorite, magnetite, secondary quartz, etc. 
Analyses F, G, and H by Hillebrand, record No. 1826. 
Si0 2 . 
A1 2 8 
Fe 2 3 
FeO. 
MgO 
CaO. 
Na 2 
K 2 0. 
H 2 Oatl05°... 
H 2 above 105 c 
Ti0 2 
PA 
CoO, NiO 
MnO 
SrO 
BaO 
Li 2 
S0 3 
FeS 2 
Cu 
66.69 
15. 40 
1.84 
undet 
.85 
.09 
.16 
3.50 
.83 
2.97 
2.11 
.08 
trace 
.09 
.11 
3.99 
98.71 
87.37 
7.44 
.09 
.18 
.12 
.10 
.14 
1.79 
.51 
1.39 
.09 
trace 
none 
trace? 
none 
.02 
trace 
1.00 
100. 24 
<;. 
78.59 
12.13 
none 
.09 
.41 
.16 
.10 
2.55 
.82 
2.47 
.12 
trace 
none 
trace ? 
none 
.02 
trace 
2.61 
100. 07 
H. 
48.47 
16.07 
4.12 
7.47 
5.96 
4.84 
2.43 
1.41 
2.30 
4.63 
1.51 
.44 
trace 
.23 
trace 
.03 
trace 
.24 
trace 
100. 15 
Heavy metals not looked for in E. 
