E. MINERALOGY AND GEOLOGY. 223 



Psittacinite^ also analyzed by Gentb, is from the Iron 

 Rod Mine, Silver Star District, Montana. It had previously 

 been mentioned as supposably a tellurate of lead and copper. 

 Now, upon actual analysis, it proves to be, not a tellurate, 

 but a hydrous vanadate of the above-named metals, contain- 

 ing some 19 per cent, of vanadic acid. It occurs in very 

 thin, cryptocrystalline coatings, varying in color from siskin 

 to olive green. 1 A^ August 25. 



THE BOKAX LAKE OF CALIFORNIA. 



It appears that the incredulity with which statements con- 

 cerning the borax lake have been received in England has 

 been considerably lessened by supplies of the material com- 

 ing to the London market. The pottery districts are espe- 

 cially interested in the discovery. Accounts set forth that 

 very extensive works are now nearly completed for the re- 

 fining and purifying of this borax for shipment. Stimulated 

 by the action of the railroad company, the borax company 

 has put up large works, and expects to turn out from twenty 

 to fifty tons of the mineral per day. The deposit of borax 

 extends over an area of eighteen miles in length by six to 

 eight miles in width, covered with crude borax to the depth 

 of three to five feet. The crude mineral averages from twen- 

 ty to forty per cent, of the pure salt. Americaii Exchange 

 and Heview^ June,\%^6. 



ACHREMATITE. 



A new mineral, bearing the title oi Achre^natite^h^?, been 

 described b}'' Professor Mallet, of the University of Virginia. 

 It came into his possession labeled " Silver ore from the 

 mine of Guanacere, state of Chihuahua, near the Durango 

 line," and, indeed, resembled one of the haloid compounds of 

 silver. Analysis, however, showed it to be a molybdo-arse- 

 nate of lead, intermixed with finely divided ferric hydrate. 

 21 A, JSfovemher^lQl 5. 



NEW MINERALS. 



Scacchi, in studying the mineral products of the eruption 

 of Vesuvius of April, 1872, has described quite a number of 

 new species. Most of these seem to be saline bodies ; one 

 is simply hydrofluoric acid, and is named hydrofluorite ; 



