1886. ] Mineralogy and Petrography. 377 l 
little crystals of aragonite and protected them from the dis- 
solving action of fresh supplies of water. Wherever an imper- 
fection in the covering allowed water to gain access to the 
aragonite substance, a concentrated solution of this was formed 
and the salt was redeposited as calcite. Its external form, 
of course, was occasioned by the shell of brown spar, which 
remained undissolved. In nearly every case studied, an internal 
kernel of aragonite was surrounded by an external covering of 
i Th 
the schists at Ottré. Hydrous anthophyllite (from Glen Urqu- ` 
hart, Scotland) is nota homogeneous substance, but is composed 
of fibers of actinolite, cemented together by a substance belong- 
ing to the chlorite group. Hydrotephroite is a mixture in various 
Proportions of at least three different substances. That which 
Occurs in greatest quantity is colorless and biaxial and is probably 
tephroite. The other substances are serpentine, chlorite and 
various manganese minerals. The hydrotephroite is probably an 
altered tephroite or some other manganese silicate. Beautiful 
rhombohedral crystals of calcite are described by R. H. Solly,? 
from the Tankerville mine, Shropshire, Eng. They contain only 
the rhombohedral and scalenohedral faces, with the former pre- 
dominating. The scalenohedral faces are bright and are cov- 
ered with little quartz crystals, while the rhombohedral faces 
contain no quartzes, but are dull and corroded. Until very 
recently our knowledge regarding the blue “sulphato-chloride 
of copper,” to which Dana in 1850 gave the name connel- 
lite, has been confined to the results of the investigations of 
Maskelyne? and Bertrand.* Lately, however, in consequence of 
discovery of new material, the crystallography of the mineral 
has been thoroughly worked up. Connellite occurs in copper 
veins traversing clay slate and granite in the Camborne district, 
situated at the west end of the granite boss in which most of the 
Productive tin mines in England occur. The mineral is not found 
massive, but only in aggregates of minute crystals, the largest 
“asuring from two to four millimeters in length. In crystalliza- - a 
m 
of they are hexagonal, containing only the simple forms P, — 
* 42 and œ P, in addition to those observed by Maskelyne— : 
oe Rendus, CHI, 1886, p: 273. ; Ce 
i Sie at Magazine, v1, May, 1885,_p- 120. 
ea osophical Magazine, January, 1863. 
Bulletin de la Soc. Min. de France, 1881, 1V. 
