THE 



EDINBURGH NEW 



PHILOSOPHICAL JOUENAL. 



Chemical Examination of the Elie Pyrope or Garnet* By 

 Arthur Connell, Esq., Professor of Chemistry, Univer- 

 sity of St Andrews, F.R.S.E., &c. Communicated by the 

 Author. 



This mineral is found on the sea-shore at Elie, in the 

 county of Fife, proceeding from the debris of trap-rocks. It 

 has been long known to Scottish mineralogists, and has been 

 regarded as one of the varieties of precious garnet, occasion- 

 ally getting the name of pyrope. It is not crystallized, but 

 occurs in angular grains, which evidently have not come from 

 any distance. Its other leading external characters, in- 

 cluding transparency and colour, agree with those of precious 

 garnet and pyrope ; the colour approaching the deeper tint 

 of pyrope. Its specific gi'avity I found to be 3-661 at 60^ I 

 am not aware that this substance has been previously ex- 

 amined chemically ; and in subjecting it to analysis, my 

 principal object was to endeavour to ascertain whether it 

 partook more of the chemical nature of pyrope, or of the or- 

 dinary varieties of precious garnet. 



The formula for garnet is now pretty well ascertained, and 

 that applied to precious garnet, /S + A S, imports about 40 

 per cent, of protoxide of iron ; and, accordingly, the ordinary 

 varieties of precious garnet, in the hands of diflFerent analysts, 

 have yielded large quantities of oxide of iron, varying from 

 25 to 40 per cent. On the other hand, the chemical consti- 



* Known to amateur collectors under the name Elie mhy. 

 VOL. XXXIX. NO, LXXVIII.— OCTOBER 1845. O 



