jF. W. Clarke — Minerals of Litchfield, Maine. 265 



In my analysis iron was not looked for, because the ignited 

 alumina, which should have contained it if present, was per- 

 fectly white. Otherwise the analyses agree tolerably well. 



Hydbonephelite, a New Species. 



Intimately associated with the sodalite is the white altera- 

 tion product mentioned in the last paragraph. So close is the 

 association, in fact, and so similar in occurrence are the two 

 minerals, that the latter has been called white sodalite by the 

 local collectors. Like the sodalite it is found in seams, and 

 yields specimens as much as two centimeters in thickness ; it is 

 white, lusterless, and has the fracture of sodalite ; and proba- 

 bly it originated from the alteration of the latter. Two speci- 

 mens of it were analyzed, which were received from two dif- 

 ferent collectors, with the following results : 



A. B. 



H 2 13-12 13-30 



SiO,_. 38-90 39-24 



A1 2 3 33-98 33-16 



CaO -05 trace 



Na 2 13-21 13-07 



K 2 1-01 -88 



CI trace 



100-27 99-65 



The alumina carried a trace of iron, and a doubtful trace of 

 manganese was also indicated. Hardness, 4*5. Fusible easily 

 to a white enamel. Soluble in hydrochloric acid, and gelatin- 

 izing upon evaporation. Fracture irregular, resembling that of 

 the sodalite. In general, the mineral may be said to have the 

 appearance of a slightly altered feldspar, minus the distinct 

 cleavage. 



These analyses left little doubt in my mind that I had a new 

 mineral to deal with, and one belonging to the zeolite family. 

 Such minerals are well-known derivatives of the nephelite 

 group, and thomsonite and natrolite have especially been often 

 noted. In composition the new product differs distinctly from 

 natrolite, but agrees in ratios approximately with thomsonite ; 

 forming, as far as chemical evidence alone goes, the soda end 

 of a series passing through rauite, up to ozarkite ; the last 

 named mineral being the nearest towards the lime end of the 

 series. A comparison of the analyses of these elseolite deriva- 

 tives is worth making, on account of its suggestiveness. The 

 ozarkite was analyzed by Smith and Brush, the rauite, from 

 Brevig, by Paykuil.* 



*Ber. der Deutsch. Chem. Gesell, vii, 1334. 



