476 



MEASUREMENTS OF CRYSTALS. 



CARBONATE OF MAGNESIA. Page 249. 

 Fig. 123. The primary, a rhombohedron. 

 PonP 107°25' {Beudant.) 



EPSOM SALT. Figs. 134 and 125. Page 251. 

 Fig. 124. The primary, a right rhombic 

 prism nearly rectangular. 



MonM' 90O30' 



Fig. 125. 



M or M'onZ 129 14 



I onl 126 52 



MAGNESIAN CARBONATE OF LIJIE. Figs. 

 126 to 128 inclusive. Page 252. 



Fig. 126. The primary, a rhombohedron. 

 P onP 106°15' 



MAGNESIAN CARBONATE OF LIME. 



Fig. 127. Bent crystals found in Herki- 

 mer and Niagara counties. 

 Fig. 128. A twin formed as in Fig. 90. 



aUARTZ. Figs, 129 to 183 inclusive. Page 257. 

 Fig. 129. The primary, a rhombohedron. 



P'onP' from 94°15' to 94°24' 

 Fig. 130. A common secondary form, a 

 six-sided prism, terminated by six- 

 sided pyramids. 

 P on r, P' on r', r on z' or r' on z 140°40' 



r onr' 120° 0' 



Fig. 131, et seq. 



P on s or z ons 151° 7' 



P on 2 or P' on z' 133 48 



ronsorr'ons 142 



