Troost on the Pyroxene. , 51 



On Pyroxene. By G. Troost, M. D. of New Harmony- 

 Professor of Mineralogy to the Philadelphia Museum. 

 Read April 23, 1827. 



The word Schorl has very properly been abandoned by 

 most mineralogists, excepting Werner and some of his fol- 

 lowers, as Jameson, and our countryman Cleaveland. A 

 word which has caused so much confusion in the science, 

 ought to have been discarded long since, as it conveys no 

 idea; and its etymology is unknown, even in the language 

 in which it was first employed. 



Among the mineral substances to which this name was 

 formerly applied, is Pyroxene, then known by the name 

 of Volcanic Schorl, the Augite of Werner and Cleaveland. 

 It is unnecessary to dwell on the term Pyroxene, which 

 signifies, according to Hauy, a guest, or stranger in the do- 

 minion of fire;* every mineralogist knows what is meant 

 by it. 



As this species has now become the type of a large min- 

 eral family, and which is, as yet, but imperfectly understood, 

 I shall offer a description of the substances now considered 

 varieties of Pyroxene, though some still think them differ- 

 ent species. In my arrangement, I shall principally follow 

 Lemar. These substances are the JUkalite, or Diopside, 

 Baihalite, Coccolite, Fassaite, or the Pyrgons, Sherzolite, 

 Mussite, and Sahlite. 



Pyroxene may be easily mistaken for Amphibole, as 

 the former is an assemblage of substances, which, at first 

 sight, seems to be very unlike, compared with each other, 

 but is distinguished from Amphibole, by the primitive 

 nucleus of its crystals, in all its varieties. This is an ob- 

 lique rhomboidal prism, in which the inclinations of the 

 sides of the prism are to each other 87° 42' and 92° 18'; the 



* Hotc ou etranger dans le domain dc feu- 



