250 Professor Necker on Mineralogy considered 



CLASS ll—AMPHIPHANOUS CRYSTALS. 



Artificial division, comprehending some metallic oxides and some metallic 

 sulphurets ; bo.th agreeing in important physical characters, and distinct from 

 the other oxides and sulphurets. 



Metallic or adamantine metal-like lustre ; streak and dust earthy ; many 

 are translucid, and even diaphanous. 



Order L— HEMATITES. 



Chem. Nat — Metallic oxides, generally the minimum of oxidation in me- 

 tals, having many degrees of combination with oxygen. 



With the blowpipe in the open tube affording neither vapour, nor smell, 

 nor sublimate, and not turning Brazil wood paper white. Except only one 

 (the red copper ore) none can be melted or reduced, without additiouj'^with 

 the blowpipe. 



Sub. Ord. I.— EARTHY METAL-LIKE HEMATITES. 

 Opake in whatever state they may be. Dark coloured dust. 



Family I. — Anhydrous earthy metal-like Hematites. 



Not giving out water either by calcination or with the blowpipe in the ma* 

 trass. 



Gen. — Oxidulated iron, (with titaniferous, chromiferous, and zinciferous 

 (Franklinite), oxidulated iron) ; axifrangible iron-ore, Mohs, {Ilmenite, Kup- 

 pfer) ; Chrichtonite ; Wolfram ; Tantalite ; black oxides of manganese (Brau- 

 nite of Haussman, and Pyrolurite of Haidinger ?) 



Appendix. — Protoxide of uranium, or pitch-ore ; ^black cobalt ochre ; Moh- 

 site (Levy) ? 



Family 2. — Hydrated earthy metal-like Hematites. 



With the blowpipe in the matrass giving out water, and experiencing a 

 change in their appearance or colour. Possessing in very small degree the 

 metallic lustre, but capable of acquiring it when polished. 



Gen Hydrate of iron, or brown iron-ore ; hydrate of manganese, or man- 



ganite of Haidinger. 



Appendix. — Yttrotantalite ? 



Sub. Ord. 2.— VITREOUS METAL-LIKE HEMATITES. 



• Translucent either entirely or only on the edges, or in extremely thin la- 

 mime. Dust-reddish, or reddish-brown, or light coloured. 



Family 1. — Infusible vitreous metal-like Hematites. 



With the blowpipe, without addition, not capable of being reduced or al- 

 tered. Scratching apatite or glass. Not soluble in acids. 



Gen.— Specular iron-ore ; rutUe, (with chromiferous and ferriferous rutile) ; 

 anatase (octahedrite, Jameson) ; red oxide of zinc. 



Appendix. — Brookite. 



