tALLER.] MINERALOGICAL NOTES. 
The following are the measured angles: 
131 
a =100 
1=110 
1=340 
1=570 
1=230 
I = 120 
[=140 
6=011 
8=111 
Measured. 
*• 
o / 
()<) 
45 00 
36 35 
35 48 
33 37 
26 30 
13 56 
03 
45 01 
/=231 33 46 
90 00 
90 00 
90 00 
90 00 
90 00 
90 00 
90 00 
33 48 
43 35 
67 39 
Calculated. 
<t>. 

/ 

(in 
45 
no 
36 
52 
35 
32 
33 
41 
26 
34 
14 
02 

00 
45 
00 
33 
41 
90 00 
90 00 
90 00 
90 00 
90 00 
90 00 
90 00 
33 54 
43 33 
67 35 
The prism /= [14-oj was noted three times as a narrow face meas- 
urements of which gave the following values for the $ angle: 
13' 49 
13 19 
14 1<> 
The dominant terminal form is {ill}, though {011} becomes at times 
fairly large. {23 1 J occurs on crystal No. 1 as minute faces and also as 
long, narrow Line face-. 
13. TOPAZ. 
Two small crystals, about 2 mm. long, which were measured, showed 
the following forms:" 5={010}, m,={ll0}, / = {l2<)|, tt={250}, ^={130}, 
y={02l}, /={01l), </ = {ll2}, s={335}, 0={lll}. The crystals were 
rounded and broken and gave, on the whole, rather poor signals. The 
measurements serve, however, to determine the forms. 
6=010 
w = 110 
Z=120 
ar=250 
-7 = 130 
y=021 
/=011 
tt=112 
8=335 
= 111 
Measured. 
lalculated. 
*. 
p - 
<f>. 
p- 
o / 

/ 

/ 
o / 
1 36 
90 
00 

imi 
'.hi 00 
61 59 
90 
00 
62 
IIS 
90 00 
13 28 
!.ii 
00 
43 
25 
9 ' 
37 00 
90 
00 
37 
07 
90 00 
32 26 
90 
00 
32 
14 
90 00 
38 
(il 
44 

00 
62 20 
38 
44 
24 

mi 
43 39 
61 56 
45 
39 
62 
08 
45 35 
61 li- 
50 
31 
62 
08 
50 46 
es 10 
63 
00 
62 
08 
63 54 
The only terminal form on crystal No. 1 is u -{112}, 
a Goldschmidt's orientation, chosen in Winkeltabellen. 
