139 



Analyses of American minerals, by Henry Seybert. 

 of Philadt Iphia. 



Of an Amphibole. 



The specimen submitted to analysis was found at 

 the Hagley powder mills on the Brandy wine, near 

 Wilmington, in the State of Delaware; it is associa- 

 ted with Quartz, and on some specimens, minute 

 portions of pyrites were observed, although this mi- 

 neral, in its external aspect, bears a strong resem- 

 blance to the Hypersthene and from that circumstance 

 was generally believed, by our mineralogists, to be- 

 long to that species. 1 am inclined to consider it an 

 Amphibole, because it is fusible, and differs essen- 

 tially, from the Hypersthene, in its chemical compo- 

 sition. 



The colour of this mineral in the mass, is dark 

 brown, 'approaching to brownish black ; when pul- 

 verized, it is grey ; lustre metallic. Slightly trans-* 

 lucent on the edges. Form indeterminate. Lamel- 

 lar. Scratches glass, and gives sparks with steel, 

 Magnetic. Specific gravity, 3. 250. Fusible be- 

 fore the blow-pipe into an opaque black glass. 



Analysis. 



A. 3 Grammes of the pure mineral, finely pulver- 

 ized, were exposed to a red heat ; after the calcina- 

 tion, the powder was of a brownish red colour, and 

 it weighed 2. 9/ grammes ; then the diminution of 



