3£ Analysis of Iron Ore. 



No. I. Spathic Iron of Baigory. 



Contexture. — The mass partly in small grains and almost 

 compact, partly in large grains, very much laminated, each 

 grain presenting distinctly a rhomboidal figure, and being 

 halt" an inch in 9ize. Its surface is bristled with large len- 

 ticular crystals nearly an inch high, which are very obtuse 

 rhomboids, and a little deformed (the equiaxis variety of 

 M. IJaiiv). These crystals form a continued mass with the 

 part not crystallized, and are evidently the same substance. 



Colour.-— Grayish white ; in some places of a deep dirty 

 fiesh red. The compact parts are the whitest. The sur- 

 face, particularly that of the crystals, is of a brownish yel- 

 low, having sometimes a slight red reflection. 



N. B. The latter colour appears to be the effect of the 

 contact of the atmospheric air; the alteration does not ap- 

 pear to penetrate into the mass. 



Transparency. — Very translucid upon the edges. 



Hardness. — A little harder than the calcareous spar. The 

 compact part is, besides, of considerable consistency ; it is 

 fresh, and by no means altered. 



Gravity — 3"83. 



This specimen appeared pure and homogeneous ; we saw, 

 however, in it some grains of quartz and pyrites, but in 

 small quantity, and very small in size. A fragment of this 

 specimen, tried in the forge, yielded a fine button weighing 

 40 per cent. It was brought from Ustelegny, near Baigory, 

 ir. the department of the Lower Pyrenees. 



No. II. Spathic Iron of Vaunaveys. 

 This specimen differs from the preceding in so far as it 

 does not present distinct crystals, although the whole mass 

 is crystalline in large grains, presenting the rhomboidal form 

 very distinctly. It is not so white in colour; it is of a deep 

 brownish yellow. It has little lustre or transparency ; it is 

 not so hard as the other, and its consistence is less. Its 

 gravity is 3-6*0. It was brought from Vaunaveys, three 

 leagues south-east from Grenoble, and nine leagues south- 

 south-west from Alevard, in the department of I sere. 



It 



