40 The American Naturalist. [January, 
ing to the albite law and cleaving well parallel to (010), the other 
being without twinning or brachy-pinacoidal cleavage, but separating 
well parallel to (121). This suggests that the common cleaving of 
plagioclase parallel to (010) may be only parting. In an albite from 
Amelia County, Va., a few parting planes parallel to m (110) and o 
(111) were observed. Lehmann’s experiment of producing the pris- 
matic parting in normal albite by throwing heated albite fragments 
into water, was repeated, but no tendency to develop the pyramidal 
parting under these circumstances was apparent. By holding in a 
vise and subjecting to a pressure in the direction of the b axis, both 
the partings (110) and (111) were produced in the Amelia albite. 
Hurlburt” describes alunite filling pockets and seams in the ore body 
at the National Belle mine at Red Mountain, Ouray County, Col. 
Analysis furnished the following results : 
SO, ,.ALO,. KO. . Na,O.. BO dnaol. Toa 
Seog PO. 4% 1i 3685, be dua 
This furnishes the formula (K Na) (Al [OH],), (SO,),, sodium and 
potassium being present in the proportions 4:7 as in the alunite de- 
scribed by Cross from the Rosita Hills.°.—Cerussite is described by 
Pratt" from the Judge Mine, Black Hawk, Meager County, Mont., in 
crystals having the forms b (010), e (001), m (110), x (012), v (031), 
i (021) and p (111). Inthe same paper are described the zircons 
from the nepheline syenite of Dungannan.and Farady, Ont. These 
are sometimes so distorted as to resemble the combination of a flat 
rhombohedron with a second order prism. Other crystals are almost 
ideally developed and exhibit the forms p (111), a (100), m (110) and 
v (221).—Ingersoll"* describes hemimorphiec wulfenite crystals from the 
turquoise mines in the Jarilla Mts., N. M. The hemimorphic charac- 
ter is indicated by the general habit and by the occurrence of the sec- 
ond order pyramid (201) only in the lower portion of the crystal. 
The pyramidal hemihedrism is indicated by the occurrence of the 
pyramid of the third order, = (313). 
15 Am. Jour. Sci., xlviii, pp- sa 
16 Am. Jour. Sci., xlviii, p. 466, 1 
1 Ibidem, xlviii, pp. 212-215. Seog 1894. 
18 Ibidem, pp. 193-195. 
