﻿On a New Alkali Hor7iblende. 85 



HORXBLENDE FROM EdENVILLE, ANALYZED BY RaMMELSBERG. 



Original 

 analysis. 



SiOo 51 



AUO3 5 



FelOg 2 



MgO 23 



CaO- 12 



Na.O 



KoO 



H;0 



Molec. R. 

 deduced 



from 

 analysis. 



98 12 



861 



56 



18 



584 



222 



12 



9 



25 



Syntag- 

 matite. 



222 



56) 



18 f 



127^ 



70 1 



12 1- 



9 I 



4j 



74 



222 



Actino- 

 lite. 



609 



457 

 152 



Calculated 

 composition. 



100 00 



Original 



analysis 



calc to 



100. 



100 00 



Here (Si02)2 = 3(56 + 18) = 222 



(K20 + RO)2 = 3(56 + 18) = 222 



(E,0 + RO) 222x3 ^^ 



(E2O + CaO)2 = 3 -^^ -2 = -^j— = 95 



(E2O + EO) 222x4 -lorr ■ 

 (Mg0)2 = 4^-^-y -^ = —^j— = 127 



(MgO)^ = 584-(MgO)2 = 584-127 = 457 



(Ca0)2 = 222 - (CaO)^ = 222 - 152 = 70 

 (NasO + K20 + H,0)2 = (E^O + Ca0)2- (CaO)2 = 95 - 

 70 = 25. But (Na20 + K20)2 = 12 + 9 = 21 



.-. (H20)2 = 4 

 Finally (SiO^)^ = (MgO + CaO)^ = 457 + 152 = 609 



Having thus deduced the molecular ratios of the syn- 

 tagmatite and actinolite, the numbers for each constituent 

 are multiplied by the corresponding molecular weights, in 

 order to obtain the theoretical relative weights of the 

 constituents of the mixed hornblende. 



