Miscellanies. 1 77 



pentine is seen in its neighborhood, and yet the Carrara marble is 

 not raagnesian. In the Isle of Skye, veins of serpentine sometimes 

 penetrate the lias, where, in the vicinity of numerous whin dykes, 

 it assumes the whiteness, and occasionally the sparkling grain, of 

 statuary marble — and here again the marble is unadulterated with 



magnesia. 



M. Dufrenoy, in a late number of the " Annales des Mines," has 

 described a similar transformation of lias into sacchproid limestone, 

 seen in the Pyrenees, 



M< 





22. PlenaJcite — new locality. (O. P. H.) — Plenakite has been 

 found, in very perfect crystals, accompanied by quartz, in the brown 

 ore of Framont. Its specific gravity is 3.00 ; hardness equal to that 

 of topaz ; cleaves readily, parallel to the faces of a rhombohedron 

 of 116° 40', according to M. Beirich. It has been analyzed by 

 Prof. G. Bizchof, of Bonn, who finds that its composition is express- 



• • 



ed by the formula Be+2Si. — Ibid. (Pog. Ann.) 



23. Anew Antimonuret of Nickel. — (Ann. des Mines, T. vti, 3e 

 liv. de 1835. Extracted from a report to the Soc. de Sc. de Gottin- 

 gen, by M. Stromeyer.) — This mineral was discovered in the moun- 

 tains of Andreasberg, with calc spar, galena, and cobalt. It resem- 

 bles copper-nickel, but is distinguished by its color. It occurs in mi- 

 nute tables, with six faces, either grouped or isolated, and presenting 

 the appearance of dendrites. Sometimes it is found in grains, rarely 

 in large masses. The crystals — seldom longer than a line — appear 

 to be hexahedral prisms, but do not admit of exact measurement. 

 Their lustre is brilliant metallic. The fracture is brilliant, uneven, 

 and conchoidal, and presents a copper red color, with a slight violet 

 tinge ; streak, a reddish brown, deeper than the surface of fracture. 

 Its hardness is nearly that of copper-nickel, as it is scratched by feld- 

 spar, and scratches fluor spar. No odor is given off under the blow- 

 pipe, and fusion can be effected only in small pieces. Heated in a 

 glass tube, antimony is sublimed. The analysis of this mineral makes 

 it probable, that it is composed of an atom of nickel and an atom of 

 antimony, and consequently it is analogous to copper-nickel, which 

 is composed of equal parts of arsenic and nickel. — D. 



24. On a double Sulphuret of Antimony and Lead; by C. Bou- 

 langer. (Ann. des Mines, T. vn, 3e liv. de 1835.) — This mineral 



Vol. XXX.— No. 1. 23 



