264 F. W. Clarke — Minerals of Litchfield, Maine. 



SiO 38-93 



A1 2 3 32-52 



CaO 2 47 



Na 9 ._ 17-02 



K,6 3-23 



H^O 2-83 



C0 2 2-95 



99-95 

 These figures plainly indicate that the mineral is a mixture 

 of elasolite and cancrinite, but do not show whether the mix- 

 ture is mechanical, or due to isomorphism. To determine this 

 point, Mr. J. S. Diller kindly undertook a microscopic examina- 

 tion of the material, comparing it in thin sections with the 

 elseolite and cancrinite "B," from the specimens of which por- 

 tions were previously analyzed. He found the mineral to be a 

 merely mechanical commingling of the two species, in nearly 

 equal proportions, and later he succeeded in separating them by 

 means of Sonstadt's solution. This fact, considered together 

 with the apparent homogeneity of the material, renders it prob- 

 able that the variations in composition of the cancrinite are due 

 to small admixtures of elseolite ; and that Whitney's speci- 

 mens were rather more so contaminated than mine. Still, the 

 entire series of cancrinite analyses are fairly concordant, and 

 confirmatory of each other. In discussing the formula of the 

 mineral, however, analysis " A " will be given preference. 



SODALITE. 



On account of its beauty, and its intense blue color, this min- 

 eral, as it occurs at Litchfield, is a favorite among collectors. 

 It is now somewhat scarce, at least in large or compact speci- 

 mens, and it ought to be carefully searched for in place. It 

 often occurs intermingled with cancrinite, forming beautifully 

 mottled masses, and also is associated intimately with the white, 

 massive alteration-product to be described later. The following 

 analysis was made, partly for comparison with Whitney's, and 

 partly to aid in the study of the accompanying white mineral. 



Clarke. Whitney. Whitney. 



SiO„ 37-33 37-30 37-63 



A1 2 3 31-87 ) 32-88 30-93 



Fe 2 C% j" 1-08 



Na 2 24-56 23-86 25-48 



K o . -10 -59 undet. 



CI" 6*83 6-97 undet. 



H 2 1-07 -.-- 



101-76 101-60 



Deduct = C1 1-54 



100-22 



