MINERALOGY. 4.55 



doubt. These latter analyses go to sliow tliat pure beryl conforms 

 to the commonly accepted formula of the species, except for the water, 

 which is uniformly present, corresponding in amount to about one- 

 half molecule, and going off only upon very strong ignition. The 

 analysis of herderite by the above authors leads to the formula 

 CaBe(F,0n)P04, in which the fluorine is partly replaced by hydroxyl, 

 the mineral yielding water when strongly ignited. In another paper 

 these authors discuss the composition of the rare octahedral fluoride 

 from Greenland, called ralstonite. The results go to show that it is a 

 hydrous fluoride of aluminium, magnesium, and sodium, with, however, 

 the fluorine in part replaced by hydroxyl. It is free from lime, which 

 has been found by other analysts, probably because their material was 

 slightly impure from the presence of a little thomsenolite. The well- 

 known pseudomorphs of chlorite after garnet from the Lake Superior 

 iron region and the superficially altered garnets from Salida, Colorado, 

 have been investigated by Penfield and Spcrr5\ 



Doelter has followed out the synthetic line of investigation mentioned 

 in the last report and has succeeded in the formation of pyrrhotite. The 

 formula obtained on the basis of a new analysis of the Sehneeberg 

 pyrrhotite, as also of the artificial compound, is FeiiSi2. The author ex- 

 presses himself as opposed to the common idea that the composition is 

 variable and regards FenSj2 as probably correct; this he separates into 

 OFeS+FcaSa or ICFeS+FeSz- Wheeler has contributed some addi- 

 tional facts in regard to the artificial lead silicate in hexagonal prisms 

 from Missouri, describing the circumstances of its formation. The 

 chemical comi)osition of a number of rare minerals, samarskite, gado- 

 linite, cerite, and others has attracted attention because of the com- 

 plex character of the metallic earths obtained from them. A number 

 of new elements have been named, and the spectroscopic investigations 

 of Crookes, Boisbaudran, and others on the yttrium group have shown 

 a complexity which the chemical examination had left unexpected. 

 The subject is especially important in connection with what Crookes 

 discusses under the "Genesis of the Elements," In the same line is 

 the interesting discovery of a new element. Germanium, in the silver 

 mineral argyrodite, an element allied to antimony, in some of its prop- 

 erties, and corresponding closely to elcasilicium in the periodic series of 

 Mendelcjeff. The properties of this element are summarized in the 

 Journ. liir prakt. Chemie, xxxiv, 177. Several contributions have been 

 made to the micro- chemical study of minerals, by Haushofer, Streng, 

 and Bohrcns, to which attention is called, though they hardly allovv of 

 being briefly abstracted here. 



NEW MINERAL OCCURRENCES IN THE UNITED STATES AND ELSE- 

 WHERE. 



Among the recent announcements of new mineral occurrences may be 

 mentioned the rare species percylite from Caracoles, Chili; molybdenite 



