vl^5,3 Scientific Notices — Mineralogi/* 1?6 



The common felspar occurs of a milk-white, yellowish-white, 

 and ochre-yellow colour. It exhibits sometimes a faintly opa- 

 lescent play of colour similar to that of Adularia. It is found in 

 a crystalline form, and in regular crystals, — (Dublin Philosophi- 

 cal Journal.) iiiiiV 



4. Description of Levei/ne, a new Mineral Species, 



The following abstract is taken from Dr. Brewster's paper, in 

 the Edinburgh Journal of Science for April, 1825. 



The mineral, of which I propose to give a brief description, 

 was kindly transmitted to me for examination about a year ago, 

 by Mr. Heuland. In the memorandum which accompanied it, 

 Mr. Heuland stated that he suspected it to be new, and upon 

 examining its optical properties, and comparing it with those 

 minerals with which it seemed to be most closely allied, I had 

 no doubt that it constituted a new and interesting species. 

 • This mineral occurs in the cavities of an amygdaloidal rock, 

 from Dalsnypen, in Faroe, and sometimes accompanies the 

 chabasie and analcime, but particularly a new variety of the 

 heulandite. 



Although this mineral is evidently a compound one from the 

 distinctness of the re-entering angles ; yet this composition is 

 not seen when examined by polarised light, through the faces 

 perpendicular to the axis. This circumstance would of itself 

 have been sufficient to show that it has only one axis of double 

 refraction, but I determined this to be the case by the direct exa- 

 mination of the polarised rings. Its double refraction is nega- 

 tive, like that of calcareous spar, and other obtuse rhomboids, 

 and though not great, yet the images may be easily separated". 

 Its ordinary refraction is a little greater than that of almond oil, 

 and very nearly the same as that of primitive chabasie. 



I have sent a specimen containing a few minute crystals of 

 this substance to M. Berzelius for analysis ; but I have not yet 

 received the results which he has obtained from them. 



It is not soluble in acids, nor does it gelatinise with them. It 

 whitens and intumesces with heat like chabasie and mesotype, 

 and, according to Mr. Haidinger's observations, it yields with 

 salt of phosphorus a transparent globule, which contains a 

 skeleton of silica, and becomes opaque on cooling. 



Cleavage, indistinct. Fracture imperfect conchoidal. 



Lustre vitreous. Colour white. Streak white. Semitrans- 

 parent. ^^; ; 



Brittle. Hardness at 4*0. -^ti-j 5)11 "io nnot jxlT .i^mr - 



I propose to distinguish this spdiires'by tlie name of LfeYey'ner, 

 in compliment to Mr. A. Levy, M.A. of the University of Paris, 

 who is already well known to mineralogists, by his crystallogra- 



