230 
ANALYSES OF ROCKS, U. S. GEOLOGICAL SURVEY. 
[BULL. 168. 
BRAZIL. 
A kyanitic schist from Serra do Gig-ante, near Diamantina, was 
analyzed at the request of Prof. O. A. Derby, who describes the rock 
in Amer. Journ. Sci. , 4th ser. , vol. 7, p. 343. Analysis by Hillebrand, 
record No. 1783. Contains kyanite, chlorite, sericite, quartz, and 
rutile. 
A. Bulk analysis of the schist. 
B. Portion soluble in hydrochloric acid. 
C. Portion soluble in strong sulphuric acid. 
D. Residue insoluble in sulphuric acid. 
The bracketed figures are deduced from other columns than the one 
in which the}^ appear. 
Si0 2 
ALA 
Fe 2 3 
FeO 
MgO 
CaO.... 
Na 2 
K 2 
H 2 at 105° 
H 2 above 105° 
Ti0 2 
PA 
Zr0 2 f 
CoO,NiO 
MnO 
SrO 
Li 2 
S 
F 
A. 
B. 
C. 
D. 
38.32 
10.78 
14.76 
[23. 56] 
28.16 
10.42 
14.77 
[13. 39] 
2.24 
[1.78] 
[2. 24] 
none 
4.02 
[3.21] 
[4.02] 
none 
12.04 
9.34 
[12.04] 
none 
.32 
.16 
.34 
[.03] 
.32 
[.03] 
.13 
1.11 
.26 
[.26] 
.85 
.55 
[.55] 
5.36 
[.55] 
6.80 
7.46 
.66 
4.93 
.10 
.20 
[4. 73] 
.47 
.09 
.47 
trace 
.47 
(?) 
[.09] 
.04 
(?) 
[.04] 
[.16] 
(?) 
.16 
(?) 
trace 
(?) 
trace 
trace 
trace 
trace 
trace 
trace? 
100. 07 
42.64 
56.66 
43.41 
