272 



DESCRIPTION OF THE APOPHYLLITE. 



III. 



Description of the Apopkyllite, Ichthyophthalmite of Dan- 

 drada and ReusSy Fischangenstein of Werner, By Mr. 

 Hauy*. 



Tish's-eye JL HE mineral, which is the subject of the present article, 



deredasazeo- ^PP^^i's to have been anciently known, and was classed as a 

 lite, species of zeolite, from its property of forming a jelly with 



acids. It had been analysed by Rinman, who mentions it 

 by the name of zeolite of Hellesta, in Sweden. The results 

 of his analysis are nearly the same as have lately been ob- 

 tained by my celebrated colleagues, Fourcroy and Vau- 

 quelin, and by Mr. Rose, whom Prussia has recently lost, 

 to the great regret of every friend of science, 

 or a feldspar, Mr. Dandrada's description of this stone does not appear 

 to me to mark it by characters sufficiently precise, to allow 

 us to decide, whether it should occupy a separate place in 

 the system, or be classed with some of the known species. 

 Mr. Brochant, after having quoted the principal features of 

 this description, adds, that the ichthyophthalmite appears 

 to have several of the characters of feldspar: and the name 

 to a species of given it by Mr. Dandrada accords with this analogy, the 

 iiame\varfor- ^'^^^^^ being equivalent to that of fish's eye, which in the 

 nierly applied: language of the old French mineralogists was applied to 

 that variety of feldspar, which I call pearly, and which is 

 the moonstone of our lapidaries, 

 but it is a dis- On examining some specimens brought hither about three 

 tinct species, years ago by Mr. Molir, I was convinced, that the ichthy- 

 ophthalmite is clearly distinguished by its mineralogical 

 characters, not only from feldspar, but from all other known 

 minerals. T shall therefore proceed to detail these, which 

 are already given for the most part in the work, which Mr. 

 Lucas, jun., had drawn up from my public lectures, under 

 the title of Tableau mcihodique des Especes minerales* 

 If^cb-iractcrs. Essential character. Divisible into a rectangular parall- 



* Jovirnal des Mines, vo! xxiii, p. 385. 



elopipedon. 



