Reéxamination of American Minerals. 43 
crystalline form is triclinic, it will be a potash albite and as such, 
an interesting species. 
@ specimens examined were received from Messrs. 'T. F. 
Seal and Wm. S. Vaux of Philadelphia. 
12. Loxoclase, identical with Orthoclase. 
The feldspar associated with pyroxene at Hammond, N. Y., 
has been named as a distinct species by Breithaupt.* Its erystal- 
line form, hardness, specific gravity and other physical characters, 
are the same as orthoclase, and the reasons for forming a new 
species of it are based upon its cleavage and chemical constitu- 
tion. ‘The latter Plattner found to be, 
Si cl a Mg Na K i 
6850 2029 067° 822 trace _ 876 308  1:28==100-70 
We have examined two varieties of it. Analyses 1 and 2 are 
from specimens taken from a large crystal and were not perfectly 
pure, owing to intimate association with a lime pyroxene ; analy- 
ses 3 and 4 are from a very pure crystal. 
2, 
1. ge 
Silica, 65°40 65°69 66°09 ae. 
Alumina, 19°48 7 : : "25 
Peroxyd of iron, 1°25 t ed ahi 0°67 
Lime, 2-26 2°36 94. Be 
agnesia, 20 25 ‘21 : 
Potash, 2°16 2:36 4°35 4°35 
oda, 7-23 7-98 781 781 
Ignition, 16 “16 0-20 0°20 
99°34 100°12 98°75 98°96 
It will be seen at a glance that the only difference between this 
mineral and orthoclase is the large amount of soda, and in analy- 
ses 1 and 2 a small amount of lime, this last, most of which is 
doubtless an impurity, alters somewhat the oxygen ratios. 
No. 1 gives t i : 13310691 
2 ; j é ‘ 1:3; 10-60 
3 : ‘ ; 1 ; 2:90 : 11:08 
d : 1:2-74: 10°83 
This slight difference in the ratio (produced by the presence of a 
considerable amount of soda) is not uncommon in orthoclase. 
In that from Hohenhagen, Schnedermann found 4:15 potash and 
7-53 soda; the flesh-red feldspar from Bathurst, Canada, gave 
Hunt 6-36 potash, 5°37 soda, and Gmelin found in the feldspar 
from Laurvig, 6:55 potash and 6-14 soda, and in that from Fred- 
icksvarn, 7-03 potash and 7-08 soda. These numbers affect to 
Some slight extent the oxygen ratio, but the correspondence of the 
minerals in physical characters denotes their identity with ortho- 
clase. Moreover, the identity of loxoclase with orthoclase 1s 
* Pogg. Ann., Lxvii, 419. 
