266 
ANALYSES OF ROCKS, U. S. GEOLOGICAL SURVEY. [no. 228. 
K. Minette. Dike, west bank of Columbia River, 1 mile above 
Northport. SR. 2 of wyomingase. Collected by F. L. Kansome, who 
furnishes the petrographic description. Analysis by W. F. Hillebrand, 
record No. 1988. Contains orthoclase, possibly some plagioclase, 
abundant biotite, pyroxene, apatite, and titanite. 
L. Brucite-serpentine rock, from quarry of the United States 
Marble Company, 12 miles north and west of Valley, Stevens County. 
Resembles ordinary serpentine, but contains also brucite, chlorite, and 
hydro -magnesite. The brucite amounts to about 60 per cent. De- 
scribed by Clarke in Amer. Journ. Sci., 1th series, vol. 15, p. 397. 
Analysis by George Steiger, record No. 2009. P. R. C. 340. 
K. 
L. 
Si0 2 
41.57 
9.75 
4.06 
4.47 
8.65 
11. 10 
1.57 
6. 10 
1 . 54 
2.30 
2. 36 
.02 
1.24 
4. 05 
.04 
.23 
.00 
.04 
.02 
.25 
.44 
.11 
trace 
.04 
13.(8. 
A1 2 3 
1.63 
Fe>0 H 
1.25 
FeO 
.19 
MS : 
56.44 
CaO 
.33 
Na 2 
none 
K 2 
none 
H 2 at 105° 
.85 
H 2 above 105° 
23. 94 
TiO , 
nndet. 
ZrO , 
co 2 
2.03 
p 2 o, 
nndet. 
CI 
F 
FeS 2 
Cr 2 3 . . 
NiO 
BaO 
SrO 
Li 2 
VoOo---- 
Less 0=C1, F 
100. 01 
.11 
99.74 
99.90 
