240 ANALYSES OF ROCKS, U. S. GEOLOGICAL SURVEY. 
11. LLANO DEL INCA, CHILE. 
[BULL. 168. 
Analyzed by L. G. Eakins, record No. 1201, and described in Bull. 
78, p. 97. 
Approximate composition of tlie mass. 
Nickel-iron 25. 8 
Troilite 10. 6 
Soluble silicates 30. 9 
Insoluble silicates 32. 6 
99.9 
Separate analyses. 
A. The nickel-iron. 
B. Silicates soluble in hydrochloric acid, calculated to 100 per cent. 
C. Insoluble silicates, calculated to 100 per cent. 
Is the P 2 5 in B derived from schreibersite ? 
A. 
B. 
c. 
Fe 
Ni 
Co 
89.77 
9.17 
.61 
Si0. 2 
28.08 
12.74 
53. 11 
2.32 
.90 
18.82 
A1 2 3 
Cr 2 3 
FeO 
42. 52 
2.90 
.20 
9.33 
1.98 
2.25 
99. 55 
• 
NiO 
MnO 

CaO 
1.75 
23.10 
MgO 
P„0- 
100. 00 
100. 00 
