Brush and Dana—Danburite from Russell, N.Y. 115 
Zz $7 103 A 2-4 142 
d 1-7 101 é 4-4 141 
x 3-7 301 
t 2-% 021 
w 4-% 041 
yp 8- 081 
qg 16-% 0161 
The following is a list of the most important angles for these 
planes, calculated from the axial ratio given above :— 
on c (001) on a (100) on 8 (010) 
k 320 90° 0” 19° 57” 10° 3° 
i 110 er 28° 34’ 61° 267 
_m 230 6 39° 14’ 50° 46” 
I 120 + A4T° 267 42° 34’ 
n 140 . 65° 20’ 24° 40’ 
2 103 16° 24” 42°36, 90° 07 
d 101 41° 27” a3" ; 
x 301 69° 197 20° 41” Ee 
t 021 43° 52” 90° 07 46° 8’ 
w 041 62° 317 27° 2 
P 081 45°) 25” 14° 35’ 
qd 0161 82° 36” ws T 26 
8 321 70° 28” 27°38" 71" 36" 
0 lll 45° 9/ 61° 397 70° 11’ 
e 221 63° 337 8° 97 ° 39’ 
u 124 bE: gee” tg 77° 64” 76° 487 
v 122 a8) 68° 18” 66° 16’ 
r 121 52° 337 57° 31’ 54° 13” 
a 142 46° 37’ i > tae 8 be 2 
6 141 4° 42° 67° 50” 34° 457 
The angle of the fundamental 
rism (J, J’) as measured on 
several crystals was 57° 7, 57 of 
A comparison of the angles of the two g cca shows 
i his will be 
5 Danburite. ‘opaz. ° 
LF 110.110 5T° 8” 55° 43° 
tAl 021,021 = 94°52 93° 11’ 
d.d’ 101,101 = 82°63’ 83° 54’ 
wa w’ 041.041 = 125° 2’ 124° 40’ 
cao 001,111 = 46° 9 45° 35’ 
cane 001.221 = 63°33’ 63° 54’ 
