S%4! Mr. T; S. Hunt's Examinations of some Canadian Minerals. 



inclining to pearly on P. Colour white passing into peavl-gray 

 and reddish white, or flesh-red in the quartzose specimens ; 

 translucent, fracture uneven. Before the blowpipe veiy diffi- 

 cultly fusible, colours the flame strongly yellow ; the analysis of 

 a pm-e specimen gave— • "i^ lo^fi j>^ifjj!-.;v i>-i,jM ir.-^ nurmn-^ •■.O'.,:. 



The results of these analyses, conjoined with its other cha- 

 racters, show this mineral to be an albite. The purity of the 

 silica obtained was verified by subsequent examination ; and it 

 may be remarked that in the first analysis the small portion of 

 silica adhering to the alumina ^vas not separated. Thomson's 

 analysis gives a much larger portion of silica, but it is evident, 

 from the description which he' has given^ that he analysed the 

 quartzose aggregate. ■{">')i ■- iioil uii/ .■.:fi/ir;,' 



Shepard and Dana have refeiTed the mineral to orthoclase ; and 

 Dana, in his last edition, by a mistake says that I have confirmed 

 the opinion, whereas I had only alluded to the apparently 

 oblique rhomboidal form of its cleavage, conjoined with the 

 beautiful opalescence, and its resemblance to the Fredericksvarn 

 opalescent felspar, which has erroneously been referred to that 

 species, as leading to the supposition that it w^as Labradorite. 



Bytownite. — This species of Dr. Thomson, founded upon spe- 

 cimens from a boulder found in the vicinity of Bytown*, has 

 been referred to a number of species. Shepard includes it under 

 pyroxene t, and Dana^ in his edition of 1844, refers it to scapo- 

 lite, while in the last edition of his IMineralogy he seems to re- 

 gard it as more nearly allied to BarsowiteJ. The specimen 

 which Dr. Holmes kindly placed in my hands was from a frag- 

 ment which had been pronounced by Dr;'Tte6!n!iSdii"tb''b(i th^ 

 species described by him as Bytownite. : ■ i>^ '.'^ >di. 

 9 1 It is massive, granular, strongly coherent, and, with the ex- 

 ception of occasional disseminated portions of black hornblende, 

 is quite homogeneous ; the gi'ains exhibit one perfect cleavage, 



■ .^ '■ ■ '- . ■(*. ■■ ^ ,. - : 

 * See Dr. Thomson's Outlines, &c., vol. i. p. 372iT9oa3{Bqo \(B'Jg-h«9q 

 t Mineralogy, Ed. 1844, p. 137- 

 X Ed. 1844, p. 523; and Ed. 1850, p. 342. 



