OF THE JEFFERSONirE. 20l 



4rCS 3 +3;^S 3 +2FS 3 forits mineralogical, & 

 4CaSi 2 +3MnSi 2 +2FeSi 3 for its chemical 

 formula. 



According to Professor Mohs' new and elegant 

 mode of classifying and describing minerals, this 

 would form a new species, in his genus Augite Spar,* 

 and come immediately after the Pyramido-prismatic 

 Augite Spar (Pyroxene, Haiiy.) On account of its 

 many cleavages I would propose to give it as a specific 

 name, the epithet of Polystome. It would therefore 

 be thus designated : 



Class I. 

 ORDER SPAR. 



Genus Augite Spar. 

 Species, Polystome^ Augite Spar. 

 Prismatic. P, unknown. Cleavage P+ 00= 106 c 

 H=4. 5 G=3. 51—3. 60. 



But until Mr. Mohs' system be more generally 

 known and approved of, it may be proper to give this 

 mineral a name unconnected with his arrangement. 

 Accordingly Mr. Vanuxem has proposed to dedicate 



* In order to make this species enter fully into the genus 

 Augite Spar, it will be necessary to extend the limits of the 

 specific gravity of this genus ; and instead of from 2. 7 to 3. 5 

 make them from 2. 7 to 3. 6. An alteration which I think Mr, 

 Mohs can by no means object to. Should the cleavages be as I 

 am inclined to consider them, the species would be described as 

 hemi-prismatic instead of prismatic, but this is an alteration 

 which it will always be time enough to make. (Vide Mohs* 

 Characteristic of Minerals, &c. Dresden and Edinburgh, 1820.) 



•t From ir»?.v§ many and rtpiet I cue. 



25 



