214 Mineralogical Notices. 



Another serpentine of similar character, from Grand Calumet 

 Island; having a pale wax color and sp, gr. 2-362-2 '38 1, aflforded 



Si Fe S[g B: 



41-20 0-80 43-52 15-40 = 100-92 



Mr. Hunt observes that the mineral has the composition of 

 marmolite of Hermannj but is not foliated; and he inchnes to 

 consider the species as not distinct from serpentine. 



7. Zircon. — Crystals half an inch thick and an inch or more 

 long occur at Grenville, along with tabular spar, calc spar, sphene, 

 pyroxene and plumbago. G. = 4'602-4"625. Color brownish red, 

 passing into flesh-red and cherry-red. Analysis afforded Mr. Hunt : 



Silica 33-7 Zirconia 67-3 =101-0 



The zirconia contained a trace of iron which was not separated. 



Celestine. — The crystallization of celestine has been studied 

 with much labor by M. Hugard, and some new crystalline forms 

 are described by him (Ann. des Mines^ [4], xviii, 3.) Mr. Hugard 

 adopts as the mean of his measurements, for M : M, 104^, the 

 angle varying between 103^ 30^ and 104^ 30'; he observes that 

 the crystals which vary most from this are chemically impure. 

 A neat crystal from Lake Erie gave him constantly less than 104^ 

 (mean, 103^ 30'); but the Lake Erie celestine contains a consid- 

 erable proportion of sulphate of barytes. The paper is illustra- 

 ted by twenty-seven figures. 



Limestone of Predazzo. — This mineral, called Predazzite by 

 Petzholdt, is a carbonate of lime and magnesia containing water. 

 This chemist deduced the formula 2CaC + MgCE[. J, Roth, by 

 his analysis (J. f. pr. Chem. lii, 346,) makes the composition of a 

 white variety, 2 6a c + Mgfl: = carbonic acid 34-11, lime 43*41, 

 magnesia 15-50, water 6-98 = 100. He obtained — 



<3 Ca Stg fl 



L 33-35 44-67 14-54 606 Si, Si, $^e 0*43 =100-00; G= 1-868 





Ca 



3Pe, Se, Y 



1^ 



CI 



1 



5316 



1-76 



41-82 



2-66 



IL 



53-79 



1*74 



41-47 



a 



HL 



53-44 



1-86 



4133 



u 



Mean, 5346 H^ 4154 2*66 



t 



II. 33-98 42-63 14-05 7-00 Si 0-29 3tl, Fe 0-49= 98-44; G= 1*013 v 



For another variety of a gray color he obtained, excluding the 

 alumina, silica and oxyd of iron, which amount to 6 per cent. 



I 29-23 35-70 24-78 10*92 = 100-63 ; G = 1-005 



IL 28-10 85-97 24-47 10-97= 97*51 ; G = 0*621 



r 



Whence he has the formula CaC + % II = carbonic acid, 27*85, | 



lime 35-44, magnesia 2532, water 11-39 = 100, Brucite occurs 

 in the marble of Predazzo, and also a variety of serpentine. 



Composition of Apatite from Snarum; G. Rose (Monatsb. 

 Akad. zu Berlin, March, 1851, 173.)— ^Analyses by M- Weber in 

 the laboratory of H. Rose : 



i; 







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