244 G. J. Brush on Amhlygonite from Maine. 



The Hebron amblygonite is translucent, and has a white color, 

 sometimes with a tinge of gray or brown. Cleavage equal, and 

 perfect in two directions meeting at an angle of 73°-74° or 106'- 

 107°. Lustre, on cleavage surfaces vitreous to sub-adamantine, 

 and on the uneven fractured surfaces faintly greasy. Specific 

 gravity 3-046, Hardness = 6. A small fragment held in the 

 flame of an ordinary stearine candle fuses readily to an opaque 

 white enamel; fusibility =2 on v. Kobell's scale. Heated in a 

 closed tube, the mineral decrepitates slightl/, and gives off traces 

 of moisture; when the flame of a blowpipe is directed on the 

 assay it fuses and acts upon the glass tube, producing a deposit 

 of silica, just above the assay, and at the same time giving off 

 water, which reacts acid, and etches the tube. In the forceps it 

 imparts to the blowpipe flame a pure lithia red color without any 

 traces of yellow ; when the assay is moistened with sulphuric acid 

 the flame is colored green on the edges indicating phosphoric 

 acid. The presence of this last substa'^nce was confirmed, by 

 fusing a fragment of the mineral in a closed tube with metallic 

 sodium, forming phosphid of sodium, which on treatment with 

 water, evolved copious fumes, with the characteristic odor of 

 phosphureted hydrogen. With salt of phosphorus it dissolves 

 with effervesence to a clear colorless bead showing the absence 

 of sihca. With borax gives a transparent colorless bead in both 

 oxydizing and reducing flame. With soda effervesces, and forma 

 a difficultly fusible mass, which, even after addition of nitre, shows 

 no trace of manganese. Heated with nitrate of cobalt it gives 

 the blue color characteristic of alumina. It is only slightly acted 

 upon by chlorhydric acid, but is readily dissolved by sulphuric 

 acid with evolution of hydrofluoric acid ; the solution gives re- 

 actions for alumina and phosphoric acid. These characters and 

 reactions are sufficient to prove the identity of the mineral with 

 iireithaupt's amblygonite. The only difference between the He- 

 bron mineral, and the amblygonite from Penio" in Saxony, isthaj 

 the former contains so little soda that it imparls a pure lithia-red 

 color to the flame, while the latter gives a flame tinged with 

 yellow. As soon as I can obtain enough of the mineral for the 

 purpose, I hope to examine the alkalies more minutely, with 

 especial reference to rubidium and csesium. These two new 

 alkahne metals have been found in comparative abundance m 

 the Hebron Lepidolite by Messrs. O. P. Allen and J. M. Blake 

 ot this Laboratory. 



It is an exceedingly interesting circumstance that the Hebron 

 mineral should occur associated with other minerals in a manner 

 Bo perfectly analogous to the Saxon amblygonite, the latter being 

 also found in a coarse granite and frequently imbedded in W' 

 dohte contammg quartz and tourmaline. The Hebron amblyg* 





. which in some specimena « 



