184 G. Pal ache — Mineralogy of Franklin Furnace, N. J. 



The Franklin friedelite agrees closely in composition with 

 that of other localities, as shown by comparison of columns 2 

 and 3. Groth's formula for the mineral, used by Dana, does 

 not well express the results of these analyses, which uniformly 

 give a higher content of manganese or its equivalents and a 

 lower content of chlorine than demanded by it. The formula 

 adopted here, H 9 (MnCl)Mn 7 (Si0 4 ) 6 , is satisfactory as to all 

 constituents save water, for which it is too low. The formula 

 H 20 (MnCl) 2 Mn 14 Si ]2 O 49 , obtained by adding one-half mole- 

 cule of water to the latter, comes nearest to the exact 

 equivalent of the analytical data but was rejected as not being 

 reducible to the orthosilicate form. Zambonini* has derived 

 for pyrosmalite and friedelite the formula 



RCl 2 .12RO.10SiO 2 4-8H 2 O 



an expression which takes no cognizance of the fact that the 

 water in these minerals is combined. The above formulas, 

 reduced to this form of expression, are : 



(1) RCl a .15R a 0.l2SiO a + 9H,0 



(2) RCl 2 .15RO.12SiO 2 + 10H 2 O 



This formula of Zambonini gives a composition very similar 

 to (2) and quite as close to the analytical results except for 

 chlorine, which is too high. It is better than (1) as to water 

 but is no closer in regard to other constituents. 



Vesuvianite, variety Cyprine: Analysis. 



Bluish green fibrous vesuvianite corresponding in character 

 with the Norwegian cyprine was found in 1905 in granite from 

 the Parker shaft. The material was carefully freed from 

 minute specks of metallic copper and had a specific gravity of 

 3-451. The analysis by Steiger, U. S. G. S., 1907, follows : 



SiO Q 





36-41 



A1 2 3 





17-35 



Fe 2 3 

 FeO 



} 



1-86 



MgO 





1-38 



MnO 





1-75 



ZnO 





1-74 



CuO 





1-85 



CaO 





33-21 



PbO 



trace 



Na 2 



0-44 



K 2 



0-50 



H 2 0- 



0-24 



H 2 + 



3-51 



F 



0-36 





100-23 



= F 



0-17 



Sum 



100-06 



This analysis agrees closely with that of the cyprine from 

 Tellemarken save in the greater amount of water and less 

 fluorine. It corresponds to the formula : 



* Zeitschr. Kryst., xxxiv, 554. 



