TABLES FOR THE DETERMINATION OF THE PRINCIPAL 
ROCK- FORMING MINERALS, 
Ti'anslated and Modified fi^vm HussaR s 
Tabellen zur Bestimmung der Mineralien. 
By C. L. Herrick. 
Table of Abbreviations. 
c = vertical crystallographic axis. 
a = brachydiagonal in orthorhombic and triclinic systems. 
R clinodiagonal in monoclinic system, 
a, b. C, == axes of elasticity. 
w = exponent of refraction in ordinary ray. } In uniaxial 
f = 
‘ in extraordinary ray. (| 
crystals. 
“ “ “ in intermediate axis, "j 
p = 
“ '' in red light. 1 
- In biaxial crystals, 
V = 
in violet light, J 
1 
Disp. = 
dispersion of axial points. 
Symbols of planes essentially as in Dana’s Text-book of Mineralogy. 
