XLI. Exainlmtions of some Canadian Minerals. By T. S. 

 Hunt, Chemist and Mimvalogist to the Geological Survey of 

 Canada *. s , m r 'it' 



THE science of mineralogy in this province is much indebted 

 to the labours of Dr. Holmes of Montreal, and Dr. AVilson 

 of Perth, who have devoted a good deal of time in exploring and 

 bringing into notice many interesting mineral species. Among 

 collections of those which were sent to Dr. Thomson of Glasgow, 

 this gentleman recognized several things which he described as 

 new species, but owing to an unfortunate want of precisioji in 

 ^iis mineralogical descriptions, their identification has been diffi- 

 cult, and mineralogical writers have been unwilling to admit 

 their claims to the rank of distinct species. Having, through 

 the kindness of the two gentlemen above named, been put in 

 possession of well-authenticated specimens of the minerals in 

 question, I have submitted them to careful analysis and obtained 

 the results which are subjoined. ,. .^ 



Fel^ars. — The first one of this geaus wAicli'jsKaU notice 

 is the mineral described by Dr. Thomson, under the name of 

 Perthitef. It is found in the township of Bathurst, and mixed 

 with quartz, forms an Eurite rock in which large cleavable masses 

 of the felspar are occasionally met with. Form, apparently 

 monoclinic. Hardness 6 (scale of Mohs.). Specific gravity 

 3*576-2"579. Of a darker colom-ed fragment 2"583. Lustre 

 vitreous, inclining to pearly ; colom* light flesh-red, alternating 

 with reddish or pinchbeck brown, the two colours forming bands 

 from half a line to a line in width, coincident with one of the planes 

 T, often however interrupted and intei'minglcd one with another. 

 The darker bands on the cleavage surface T exhibit, when viewed 

 perpendicularly, a golden reflexion like the variety known as 

 aventurine felsjjar. The colours of the mineral become much 

 darker on exposure to the action of the weather. The results 

 which follow were obtained from freshly-broken light -coloured 

 fragments, and the mineral reduced to a fine powder by elu- 

 triatiou, was dried in one analysis at 300° F., and in another 

 at the ordinary temperatm-e over sulphuric acid. The earthy 

 constituents were determined in the ordinary manner after 

 fusion with carbonate of soda, and the alkalies by decomposing 

 the mineral by the aid of fluor spar and sulphuric , acid. r._ it * 



r,,,.* Communicated by the Author. 

 "t Phil. Mag. 1843." xxii. p. 18.'^ 



