374 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Apr. 26, 



rals. As regards the general character of the gangue of the mine, 

 we are struck by the absence of Pluor, and the comparative rarity 

 of Blende and Heavy Spar. The last-named species we might fairly 

 expect to be present in considerable abundance, as baryta is present 

 in such large quantity in the Harmotome and Brewsterite. 



During the last six years a new mine, caUed Corrantee, has been 

 opened, at a distance of some two miles westward from Whitesmith, 

 but at the other side of the hiU. It is, however, apparently on the 

 same lode that is worked in Glen Strontian, but is situated entirely in 

 the gneiss. I first visited this mine in 1866, and noticed the pre- 

 sence of the barytic Zeolites. Since that time some very beautiful 

 specimens have been obtained from it, notably of Caleite, in the 

 form of scalenohedrons terminated by rhombohedrons, and coated 

 with Harmotome. 



Among other specimens I found some crystals of Harmotome 

 closely resembling those from Andreasberg, in fact true Cross-stone. 

 These were irregularly distributed over a mass of very acute scale- 

 nohedrons of Caleite, and associated with minute hexagonal prisms 

 apparently terminated by a basal plane, and perfectly transparent. 

 When I first noticed these crystals I felt sure that I had discovered 

 a new locality for Brewsterite; but on testing the mineral in the 

 blowpipe I found that it did not swell up, and that it gave a simple 

 baryta-flame. The borax-test proved abundantly that it was a 

 Zeolite. These results made me suspect that it was only a new form 

 of Harmotome. 



Not being myself able to analyze it, from want of time, I requested 

 my friend Dr. J. E. Reynolds, Keeper of the Minerals in the Royal 

 Dublin Society, to examine it. 



He detected that the termination of the prisms is not a single plane, 

 but consists of two planes inclined to each other at a very obtuse 

 angle. 



He therefore broke up a large specimen, picked out carefully all 

 the crystals which exhibited this peculiar termination to the prisms, 

 and subjected them to analysis. 



He only succeeded in obtaining 1 '5 gramme of the mineral by this 

 method, a quantity quite insufiicient for a complete analysis, inas- 

 much as, owing to the necessity of determining the alkalies, he was 

 obliged to decompose the mineral by acid, and therefore could not 

 ascertain the amount of water present. 



The following Table gives the best analyses of Strontian Harmo- 

 tome which have as yet been published ; and it will be seen how 

 closely Dr. Reynolds's analysis agrees with them. 



A. B. C. D. 



SiO, 47-74 47-62 47-60 48-02 



Al.,03 15-68 16-94 16-39 17-42 



Fe;03 0-51 0-65 



BaO 21-06 20-25 20-86 20-17 



CaO trace 



KO 0-78 1-00 0-81 \ (.(.c. 



NaO 0-80 1-09 074 / "o^ 



HO 13-19 13-45 14-16 13-77 (water andloss). 



99-76 100-25 101-21 100-00 



