CLARKE.] 
IGNEOUS AND CRYSTALLINE ROCKS. 
51 
F, G. Two samples of websterite, Hebbville, 6 miles west of Balti- 
more. Wehsterose. 
H. Bronzite from G. 
I. Diopside from G. 
The rock consists entirely of bronzite and diopside. Analyses by 
T. M. Chatard, record Nos. 1094, 1123. 
J. Websterite, Oakwood, Cecil County. Cecilose. Composed of 
hypersthene and diallage. Analysis by W. F. Hillebrand, record No. 
1755. Described by A. G. Leonard in Amer. Geologist, vol. 28, 
p. 135. 
K. Cortlandtite, Ilchester, Howard County. Cortlandtose. Analy- 
sis by W. F. Hillebrand, record No. 1122. Published by Williams in 
Fifteenth Ann., p. 674. The rock consists of olivine, pyroxene, and 
large hornblende crystals, the latter considerably altered to talc. 
F. 
G. 
H. 
I. 
J. 
K. 
Si0 2 
53.98 
1.32 
1.41 
3.90 
22. 59 
15. 47 
undet. 
undet. 
.09 
.83 
.15 
trace 
52. 55 
2.71 
1.27 
4.90 
20. 39 
16.52 
} - 
| 1.09 
.14 
trace 
54. 53 
1.93 
1.70 
8.92 
29.51 
2.25 
| 1.14 
undet. 
trace 
51.80 
2.21 
•1.29 
3.50 
17.76 
20.99 
undet. 
undet. 
| .65 
.13 
trace 
53.21 
1.94 
1.44 
7.92 
20.78 
13. 12 
.11 
.07 
.14 
.87 
.26 
trace 
trace 
.03 
.20 
} •« 
.22 
none 
none 
trace 
. 03 
.10 
39.20 
A1 2 3 
4.60 
Fe.,0., 
3.45 
FeO 
6.15 
MgO 
31.65 
CaO _ 
3.23 
Na 2 
.42 
K 2 
.14 
H 2 at 100° 
.50 
H 2 above 100° 
9.38 
Ti0 2 
.52 
P 2 5 
trace 
Zr0 2 
V 2 3 
Cr 2 3 
.53 
trace 
.44 
.30 
.51 
.41 
ISfiO 
.30 
3oO 
MnO 
.21 
24 
.28 
trace 
.20 
3rO 
BaO 
trace 
res 2 
X) 2 
100. 48 
100. 52 
100. 56 
98.84 
100. 47 
100. 15 
— - 
