MINERALS. 279 
100.28 | 99.77) 99.76 | 100.01 
- 380 1% -13 - 04 
99.98 | 99.60 | 99.63 99. 97 
The following analyses represent alteration products of lithia tourmaline: 
L. From the Rumford rubellite. 
M. From the rubellite of Hebron, Maine. 
N. Pink tourmaline, Pala, San Diego County, California, partly altered. 
0. Tourmaline N, almost completely altered. Analyses L, M, by Riggs; N, O, by 
Schaller. 
a By difference. 
MAGNESIAN: AND IRON TOURMALINES, 
Analyses A to L by R. B. Riggs. See Bull. 55. 
A. White to light-brown crystals, Dekalb, St. Lawrence County, New York. 
Sp. gr., 3.085. 
B. Brown tourmaline, Gouverneur, St. Lawrence County, New York. 
C. Cinnamon-brown crystals, Hamburg, New Jersey. 
D. Brilliant black crystals, Pierrepont, St. Lawrence County, New York. Sp. gr., 
3.08. 
E. Dark-brown crystals, Orford, New Hampshire. 
F. Dark-brown crystals, Monroe, Connecticut, 
