CLARKE.] 
IGNEOUS AND CRYSTALLINE ROCKS. 
43 
F, G. Two samples of websterite, Hebbville, 6 miles west of Balti- 
more. 
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. Composed of hypersthene 
and diallage. Analysis by W. F. Hillebrand, record No. 1755. 
Described by A. G. Leonard, but hitherto unpublished. 
K. Cortlandtite, Ilchester, Howard County. Analysis by W. F. 
Hillebrand, record No. 1422. Published by Williams in Fifteenth 
Ann., page 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 
} .27 
| 1.09 
.14 
trace 
54.53 
1.93 
1.70 
8.92 
29.51 
2.25 
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 
| .03 
.22 
none 
none 
trace 
.03 
.10 
39.20 
4.60 
3. 45 
6. 15 
31. 65 
3.23 
.42 
.14 
.50 
9.38 
.52 
trace 
ALA 
FeA 
FeO 
MgO 
CaO 
Na 2 
K 2 
| 1.14 
undet. 
trace 
H 2 Oatl00°... 
H 2 above 100° 
Ti0 2 
PA 
Zr0 2 
V,0, 
Cr 2 3 
.53 
trace 
.44 
.30 
.51 
.41 
.30 
NiO 
CoO 
MnO 
.21 
.24 
.28 
trace 
.20 
SrO 
BaO 
Li 2 
trace 
FeS 2 
C0 2 
100.48 
100.52 
100. 56 
98.84 
100. 47 
100. 15 
