Brush and Dana— Fairfield County Minerals. 43 
Orystalline form.—Of the few terminated crystals obtained, 
three only were suitable for measurement and only one of these 
had the terminations complete. These were 4. 
planes in the prismatic zone are in the 
reason- 
ably good. The crystals show occasionally false planes, bearing 
no relation to the axes of the crystal, and which are evidently 
p. agien of portions of adjoining crystals. : 
he crystals belong to the Monoctinic System and their 
habit is shown in figure 4. The axial ratio was obtained from 
the following fundamental angles :— 
Cxv'¢€ == OOLN01L = °64° 48” 
GAd: = 106% 110. =  -60° 27 
Qne = 1064 001 = 71° 467 
These angles are good, though a little less so than those given 
for oe TSN probable error, however, does not exceed 
+1’. he axial ratio is: 
c (vert.) b ie. 
0°80367 0°53846 1-00000. 
The observed planes are: 
c, O, 001. foe ae 
b, it, 010. e 14, O11, 
i, 100. * Ss) TIL 
The following are the principal angles, both calculated from 
the above data, and as measured on the same crystal (1) and on 
the two others (2 and 8): 
Cc 
w Measured. 
IP, 110,110, =120° 54’ ine 52’ (3) 
I~I’, 110.110, = 59° 6’ 120° 54 
@xc, 100,001, = 71° 56’ #7 1° 56’ 71° 55’ (3). 
@xe 1004011, = 79° 37’ 19° 36” 
' ee ae *60° 27 
aad, 100 ~ 110, — 60 aT’: } 60° 26’ 
a~p, 100.211, = 52° 49” 52° 457 
bae, 010.011, = 35° 12” 
bam, 010.110, = 29° 33’ 
bap, 010.211, = 48° 33” 
cae, 0014011, = 64° 48’ #54° 48” 54° 49” (2) 
