HALLER.l MINERALOGICAL tfOTES. 
The following- are the angles obtained: 
133 
Measured. 
Calculated. 
<f>. 
p- 
<!>. 
p- 
h -010 
o / 
34 
56 10 
90 20 
34 
34 
34 
o / 
90 00 
90 00 
60 22 
15 33 
22 00 
29 00 
o / 
00 
55 34 
90 00 
00 
00 
00 
o / 
90 00 
m— 110 
90 00 
e —101 
60 04 
r —014 
16 34 
q -013 
21 39 
* -012 
30 46 
Many other signals between these were seen in the striated brachy- 
donie zone, but they probably belong" to no definite face. 
The analysis gave the following results: 
Ratio. 
As 
39.84 
18.46 
12. 45 
20.23 
9.38 
} 
0.94 
S 
1.04 
Fe 
Co 
1.02 
Insol . . 
100. 36 
Nickel and antimony were not determined, though the} T were shown 
not to be present in any quantity. The 
ratio of the cobalt to iron is 31:20 or 3:2, 
so that the formula may be written 
instead of 
Co 3 Fe 2 As 5 S 5 , 
R AsS, R=(Co, Fe). 
17. PYRITE. 
A small group of pyrite crystals from 
Spanish Peaks, Colo., kindly presented to 
the writer by Mr. R. Sargent, showed, on 
examination, a rich combination of forms, 
especially in the pyritohedral zone. The faces are for the most part 
not striated and give excellent reflections. Jn size the crystals reach 
a maximum of about one-half centimeter in diameter. They were so 
closely crowded together that only a small portion of each crystal 
was developed; consequently, when the group was broken, a few frag- 
ments showed only one or two zones of faces. 
