Geology and Mineralogy. 155 
esac vanities of garnet and arrived at results cepencially the 
m of M. Mallard. Sections of i Seve als of aplome, 
GeRnere pth topazolite show two optic axes with an angle of 
about 90°. The ouvarovite is regarded as made up of twelve 
pyramids having the faces of the crystal as their base and their 
vertices at the center. The Sa uae yg alee of aplome and topaz 
h 
from this that the union of the four crystals which form together 
the same rhombic face is more intimate than that of the twelve 
complex rhombohedral pyramids among themselves. That this 
is me true explanation 0 of these facts may perhaps be questioned. ° 
. Brief notices of some recently described minerals,—CHat- 
es ITE. new species described by M. DesCloizeaux, from 
mined, owing to lack of material, but preliminary trials by M. 
Damour show it os ve essentially a hydrated selenite of copper.— 
,A 4,18 
TrrrocHorirE. “Described ie Frenzel ek unknown. Phy- 
sical character as fo llows: Ma ve olumnar structure ; 
Lautrre, Also described by bisa Blac the ping Radar 
schacht at Lauta, near Marienberg, 8 
with oe ee fibrous, or granular nema Ae ok = Or 33; 
= 49 ; luster metallic ; ; color iron-black; streak black. An 
mARE ng gave: As 42°06, 8 18°00, Cu 27°66, Ag 11°74 =99°40. 
