330 Knopf and Schatter — Two New Boron Minerals. 



7RO.Fe 2 3 .H g ().4B : .03 does not lead to any simple constitu- 

 tional formula. 



Paigeite. 



The specimens of paigeite from Brooks Mt. show a coal- 

 black lustrous mineral of a laminated appearance. No distinct 

 ciwstals were seen, but the entire mass has a crystalline appear- 

 ance and in thin sections is seen to be composed of innumer- 

 able hair-like needles, often forming radiating groups. The 

 characteristic appearance of paigeite is shown in the photomicro- 

 graph (hg. 2). The mineral apparently possesses an imperfect 



Fig. 2. Paigeite fibers embedded in tourmaline. Colorless mineral is fluor- 

 ite. Magnified 60 diameters. 



cleavage, is soft, hardness about 3, with a density of 4'Tl. 

 The color is coal-black, streak the same, and the luster very 

 shining. It is readily soluble in HC1 and HF and in its pyro- 

 gnostic properties resembles hulsite. 



Analyses of paigeite from Brooks Mt. gave the following 

 results: 



Analyses of Paigeite. 



1 2 3 4 Av. Anal. 



FeO 43-91 44-30 45*82 43'87 44-48 



MgO 1-70 1-22 1-39 1-44 



Fe 2 3 16-72 



Total iron as Fe 2 3 66-26 65*95 66-22 



H„0 ... 2-03 2-03 



B 2 "O s 20-89 20-89 



Insol 14-25 14-46 14-35 14'35 



99-91 



