Mineralogy and Petrography. 1021 
MINERALOGY AND PETROGRAPHY.* 
_ New Minerals.—Langbanite is the name applied by G, Flink? 
ta mineral which occurs in small black hexagonal crystals in a 
granular limestone at Långban, Sweden. In habit it is tabular 
_ prismatic, with the. prism faces but slightly developed. Its 
Tatdness is 6.5, specific gravity = 4.918. Its axial ratio is 
151.6437. - Its analysis yielded,— 
As Sb,0, SiO, MnO FeQ > 
| 15.42 10.88 -00 . 
The discoverer regards it as silicate of manganese (Mn,SiO,) 
H,O Loss at 110° 
21.62 9.84 21.20 
n and water of crystallization. 
Pe Phillipsite. 
Si0,) ESIOS, 344 (SiOs)s 
Sa Al,(SiO3)s 2Ca(Si 
) a! Ca(SiO,) + 4H,O K,(Si0,) + Aii H,O 
estigations of American Minerals. Mica—Prof. 
he U. S. Geological Survey, has recently tarn 
in ques- 
omelane from Baltimore, Md., and from Litchfield, 
nite from Rockport. Their compositions may be 
by the formulas 
Iaa I . In" Si 
Og (Rockport); R'R”R” Si O, (Baltimore); and RRR „SiO 
: (Litchfield). 
aiy ng W. S. BAYLEY, re Wisconsin. 
: ür Krystallographie, xiii., 1887, p. 1. 
* Neues Jahrb, f. Min., T, Band., v., 1887, P- 318. 
ir, Sci., xxxiv., Oct. 1887, p. 131. 3 
