510 



Prof. Haughton^s Notes on Mineralogy. 



nei-al from the Isle of Skye, Beudant's analysis of hypostilbite 

 from Faroe. 



Hypostilbite {sec. Beudant). 



100-23 



This analysis agrees with Beudant's and my own, except as to 

 the quantity of water present, and I think it would be very difR- 

 cult to make a satisfactory mineralogical formula from any of the 

 analyses. Hypostilbite is not well established as a distinct mi- 

 neral, and should be considered as an altered form of stilbite. 



I shall conclude this note by adding an analysis of some fine 

 crystals of stilbite from the Nerbudda Valley, Hindostan, recently 

 sent home by Mr. Jacob, C.E. 



98-46 

 This leads to the well-known formula for stilbite, which may 

 be considered as a Hydrated Lime Orthoclase, 



CaO, Si03 + AP03, 3Si03 + GHO. 

 If we are to consider hypostilbite as a distinct mineral, it should 

 be regarded as a Hydrated Lime Oligoclase, with the formula 

 CaO, Si03 + AP03, 2SiOs + 5HO. 



