1278 General Notes. [ December, 
MINERALOGY' . Bes 
MINERALS OF THE CRYOLITE GROUP FROM CoLoRADO.— W, 
Cross and W. F. Hillebrand? who have previously described 
a number of interesting species from the vicinity of Pike's ` 
Peak, have identified cryolite and several allied fluorides 
from the same region, and have given a very exhaustive ac- 
count of their method of occurrence, physical and crystallo- 
graphic characters, and chemical relations. Cryolite occurs in 
massive aggregates of crystalline individuals, and when fresh has 
zone of purple or green fluorite, and next to this 
veins of Altenberg, Saxony. Prosopite was also 
crystals upon altered pachnolite in the quar a 
The identification of this rare species is of much interest 
authors deserve much credit for the care and skill ib POS 
have applied to the study of the minerals in the nega? 
Pike’s Peak. lon 
Tue Uranium Minerarts—Heinrich Baron von F on 
published* an exhaustive paper on the decomposition teu 
uraninite, and on the chemical separation of ura a sions: 
and other substances, and comes to some important COR aa 
interest to mineralogists. The uranium minerals € a 
1 Edited by Professor H. CARVILL Lewis, Academy of Natural SE a 
delphia, to whom communications, papers for review, etc., should be se 
3 Amer, Jour. Sc., Oct., 1883. 
3 Zeits. f. Kryst., VIL n : 
4 Jahibuch d, K, K, Geolog. Reichsanstalt, 1883, B. XXXII, Pp Fr 
