202 



IntclUsence and Miscellanies. 



nated through the stone, and almost completely lining its 

 cavities in little grains and semifused crystals, yet such is 

 their minuteness, that it scarcely forms a more considerable 

 ingredient than the meteoric iron. 



Mineralogical description. 



Form : distinct crystals, of which I obtained three, of suffi- 

 cient dimensions to enable me, with the aid of a magnifier, 

 to ascertain their shape, and to determine the value of their 

 principal angles by the reflective goniometer. The most 

 perfect of the three, offered only the sides M, M', and their 

 four adjoining pyramidal planes c, c, c', and c', with the trun- 

 cature a, as seen in the annexed diagram : — the other planes 

 of the figure were inferred from the relations of these, the 

 regular six-sided prism being known to be the fundamental 

 form of the species. 



M, on M', 120.« 



— on c, 153.30'. 



c, on a, 117.30. 



Structure : cleavage imperfect. Brittle. Lustre steel 

 like and splendent. Color steel grey upon the crystalline fa- 

 ces ; copper yellow on fractured surfaces. Extremely sub- 

 ject to tarnish, of which the steel blue and red form the most 

 frequent colors. 



Hardness : not impressible by steel. 



Chemical characters. 



Before the blowpipe, on charcoal, it enters into immediate 

 fusion, emitting at the same time sulphureous fumes : the 

 globule formed assumes a deep red color while hot, but turns 

 to a dull black, and becomes strongly magnetic on cooling. 



To 0.4 grs. in powder was added muriatic acid. The 

 flask was fitted with a tube dipping into a solution of ace- 



froiu tlieir gangue, for the purpose of submitting them to trial before the 

 blowpipe. Their intense green color reminded nie oi malachite. 



