314 Notice of Warwickite. 
the vicinity of the first, in which several forms half an inch in 
diameter have occurred, although the last discovered crystals are 
wanting in lustre when compared with those first mentioned, 
and are moreover in a somewhat decomposing condition. They 
are associated with large crystals of black spinel, which are also 
dull from partial disintegration, a change apparently induced from 
the intermixture of serpentine. 
A more close attention to the mineral above mentioned, both 
as relates to its mineralogical and chemical properties, than I have 
heretofore been able to bestow upon it, has convinced me that it 
is fully entitled to constitute a new species, which I designate 
Warwickite, from its original locality. 
Mineralogical Description. 
_ Primary form. Oblique rhombic prism. M on M=93° to 94°. 
Secondary form. The primary having its obtuse lateral edges 
truncated, and its acute ones, beveled. The summits rounded. 
Cleavage parallel with the longer diagonal perfect. The cleav- 
age planes thus obtained are finely striated vertically, and exhibit 
very distinct, oblique cross cleavages. _ Fracture uneven. 
stre eminently metallic-pearly, of a copper-red color on the 
perfect cleavage-faces ; in other directions, only vitreous in mode- 
rate degrees. Color dark hair-brown to iron-gray. Opake, except 
in very thin fragments, when it is translucent and transmits @ 
reddish-brown light. Streak dark chocolate-brown. Decompo- 
sing crystals are nearly iron-black with a faint tinge of purple. 
- Brittle. Hardness=5.5...6.0. Sp. gr. 3.29. 
Chemical Description. 
When heated on charcoal before the blowpipe, it does not fuse, 
but simply assumes a lighter shade of color. With borax, it dis- 
solves with effervescence, affording while hot a yellow semi-opake 
glass, which on cooling changes to a pale green and becomes 
clear. It renders carbonate of soda opake, at the same time im 
parting to it a dull yellow tinge. In microcosmic salt, it melts 
with effervescence, the globule being blood-red while hot, from 
which it passes through orange-yellow as it cools, and finally be- 
comes reddish-gray and opake. On being pulverized and heated 
in a glass tube, it emitted moisture and hydro-fluoric acid. The 
a few drops of sulphuric acid. | WERT was 
