174 
PROCEEDINGS OE SOCIETIES. 
ANALYSIS OF ANORTHITE FROM THE URAL MOUNTAINS. BY ROBERT H. 
SCOTT, A.B.T.C.D. 
Professor G. Eose having requested me to undertake the analysis of 
the Felspar of a Biorite which forms the Konschekowskoi Kamm, near 
Eogoslowsk, in the northern Ural Mountains, I accordingly did so, and 
found it to he Anorthite; the results of the analysis being:— 
Silica, . . . 
. . 46-794 . 
O. ratio. 
. 24-2969 
Alumina, 
. . 33-166 . 
. 15-5028 1 
}> 17*6338 
Peroxide of Iron, 
. . 3-043 . 
. 2-1310 j 
Lime, . . . 
. . 15-968 . 
. 4-5408 1 
| 
Magnesia, . . 
. . trace. 
1 
► 4-9632 
Potash, . . . 
. . 0-554 . 
. 0-0939 ( 
Soda, .... 
. . 1-281 . 
. 0-3285 J 
1 
100*806 
The specific gravity of the portion analyzed was 2*72. This mineral 
is granular, not exhibiting distinct crystalline faces, and is soluble in 
muriatic acid. 
The second constituent of the Biorite, a greenish-black hornblende, 
has been analyzed by Professor Eammelsberg (Pogg. Ann. 1858, iv. 
p. 441). His analysis gives— 
Titanic Acid, .... 
1-01 
O. ratio. 
Fluorine,. 
0-25 
Silica,. 
44-24 . 
. 22-97 
Alumina,. 
8-85 . 
. 4-13 
Peroxide of Iron, . . 
5-13 . 
1-54 
Protoxide of Iron, . . 
11-80 . 
2-62 
Lime,. 
10-82 . 
. 3-09 
Magnesia, .... 
13-46 . 
5-38 
Soda,. 
2-08 . 
. 0-53 
Potash,. 
0-24 . 
. 0-04 
Loss by ignition, . 
0-39 
98-27 
The mineral has a specific gravity of 3-214. It is compact, with 
perfect cleavage. 
The Biorite itself is very coarse-grained, the minerals being distri¬ 
buted through it in irregular masses. It contains also a little quartz, 
and some brownish-white mica. 
The President stated that Mr. Scott’s analysis confirmed his own 
analysis of Anorthite from the Carlingford Mountain. 
The Society then adjourned to November. 
