V 



Miner alogical Notices. 215 



Calculating the lime phosphate from the amount of phosphoric 

 acid, the chlorid of calcium from the chlorine, and the fluorid from 

 the remaining lime, G. Rose deduces for the composition 



Ca^? Ca CI Ca F Pe Se t 



90-66 4-n 3-07 l-'79 



In the analysis formerly made by G. Rose, this chemist found 

 in the Snarum apatite, lime 5475 and chlorine 2-713, whence he 

 deduced 



Ca^P CaCl CaFl 



9M3 4-28 4'59 



agreeing very nearly with the analysis by Weber. Weber's re- 

 sults with the new modes of determination of phosphoric acid 

 therefore confirm the earlier deductions of Rose. 



Diaspore. — Occurs according to Prof. C- U. Shepard, (loc. cit. 

 P- 319,) at the fluor spar and topaz vein at Trumbull, Conn., in 

 thin or 6-sided tables, flattened parallel to the shorter diagonal. 

 It is the species formerly announced by Prof. Shepard as euclase- 



M: M=:130o30^M:o = 125O; 0:0 = 152030^- o : on ocPx 

 ^ 104° 30^ H. =7-7-5. G.=3-29. Analysis afforded Prof Shep- 



ard, Alumina 84-9, water 15-1 = 100. 



Hydrargillite from Brazil. — Yon Kobell announces this min- 

 eral (J. f. pr. Chem. 1, 493, 1850,) as occurring in Brazil, and as 

 having been mistaken for wavellite. It occurs in spheroidal con- 

 cretions, having a radiato-lamellar structure, giving some indica- 

 ' tions of rectangular prisms. Color grayish to yellowish-white j 

 translucent ; lustre pearly inclining to vitreous ; hardness between 

 calc spar and fluor spar. Dissolves wholly in concentrated sul- 

 phuric acid. Composition according to von Kobell: — alumina 

 with a trace of silica 67-26, water 32-39 = 9965, and giving the 

 formula Xi tP. It was found to contain no phosphoric acid. 



A New form of Compound Crystal of Quartz. — M. G, Rose has 



described a compound crystal of quartz (Monatsb. Akad. zu Berlin, 

 March, 1851, p. 171), which consisted of four crystals, one a 

 central, and each of the others united to the first correspondingly 

 by a primary rhombohedral face, the axes of the central and the 

 others, making an angle equal to the complement of double the 

 angle between a rhombohedral plane in the primary and its vert- 

 ical axis; the latter angle is 38^ 13' according to Knpffer, whence 

 the inclination of the axes is 103° 34'. The primary faces of the 

 pyramid are larger than those alternate, and the prism has its 

 alternate planes larger so as to approach a 3-sided form. The 

 specimen is from the serpentine of Reichenstein, and is associated 

 With small crystals of arsenical iron. 



Serpentine. — G. Rose has examined crystals of serpentine in 

 the collections of Berlin (Monatsb. Berl. Akad.,) and sustains the 



