352 
IOWA ACADEMY OF SCIENCE Voe. XXIX, 1922 
The specific gravity is 2.70. The specimen is not a dolomite, 
but a magnesian limestone. 
7. Specimen from Sonnenvendjoch, Tyrol, Austria. It is a 
compact, massive greyish rock. 
PER CENT 
Si0 2 . . . 
Fe 2 Os . . 
AI 2 O 3 . . 
CaCOs . 
MgCOa 
Total 
3.58 
3.18 
0.00 
73.75 
19.59 
100.07 
The specimen is also a magnesian limestone. The specific grav- 
ity is 2.74. 
8. Specimen from Reiterkogel, near Brixlegg, Tyrol, Austria. 
It is a greyish-white crystalline, compact rock. 
Si0 2 . . . 
Fe 2 0 3 . . 
ai 2 o 3 . . 
CaC0 3 . 
MgCOs 
Total 
PER CENT 
. 0.35 
. 3.40 
. 1.85 
. 52.01 
. 42.52 
.100.13 
The specific gravity is 2.80. The rock is a fairly typical dolo- 
mite. 
9. Specimen from Zirler Klamm, Tyrol, Austria. It is a 
black, massive rock and bears a rsemblance to quartz, having a 
conchoidal fracture. 
. Si0 2 . . . 
Fe 2 0 3 . . 
A1 2 0 3 . . 
CaC0 3 . 
MgCOs 
Total 
PER CENT 
. 14.50 
. 9.50 
. 7.00 
. 48.55 
. 20.39 
. 99.94 
The specific gravity is 2.80. The rock contains relatively large 
amounts of silica, iron and alumina. 
10. Specimen from Kloster Alpe, Tyrol, Austria. It is a 
grey, compact, massive, hard variety, one side of which seemed to 
have been fused. 
PER CENT 
Si0 2 0.75 
Fe 2 Os 4.30 
AkOs 3.00 
CaC0 3 85.73 
MgCOs 6.19 
Total 99.97 
The specimen is a magnesian limestone. The specific gravity 
is 2.70. 
11. Specimen from Little Falls, New York. Light grey in 
color, uniform throughout the entire specimen. 
