126 PHYSIOGRAPHY. 



Chrome-Ore. 



Lustre imperfectly metallic. Color between iron-black 

 and brownish-black. Streak brown. Opake. 



Brittle. Hardness = 5-5. Sp. gr. =4'498, a variety 

 from Stiria. 



Compound Varieties. Massive : composition granular, 

 the individuals being of various sizes, and generally firmly 

 connected. 



1. Alone before the blow-pipe, it is infusible, but acts upon tbe mag- 

 netic needle after having been exposed to the reducing flame. It is with 

 difficulty wholly soluble in borax, to which flux it imparts a beautiful 

 green color. 



2. Analysts. 



By VAUQTJELIJN". By KLAPROTH. 

 Oxide of chrome - - 43-00 - - 55-50 

 Protoxide of iron - - 34-70 - - 33-00 

 Alumina - - 20-30 - - 6-00 



Silica 2-00 - - 2-00 



3. The varieties of Chrome-Ore have been hitherto found only in 

 serpentine, in irregular veins and beds, which appear to be of contempo- 

 raneous formation with the rock itself. 



4. This species was first found in the department of du Var in France, 

 where it formed nodules and kidney shaped masses. In Stiria it occurs 

 in the Qulsen mountain near Kraubat, in serpentine, in very irregular 

 veins. Other localities are, Portsoy in Banffshire, and at Buchannan in 

 Stirlingshire, in Scotland ; in the latter place imbedded in limestone : at 

 Unst and Fetlar in the Shetland isles, in Silesia, Bohemia and the Ural- 

 ian mountains. In the United States a^very abundant deposit exists at the 

 Bare Hills near Baltimore, where it occurs in veins or masses in serpen- 

 tine. The crystals are found at the same place in channels worn by 

 water about the base of the hill. At Hoboken in New Jersey, it is found 

 both massive and in crystals, imbedded in Serpentine and Dolomite ; and 

 under similar circumstances at Milford and West Haven, (Conn,) 



5. The Chrome-Ore is highly valuable for extracting the oxide of 

 chrome, which is employed either alone, or in various combinations 

 with the oxides of other metals, as cobalt, lead, mercury, &c., both 

 for painting on porcelain, and for painting in oil. It yields green, yellow 

 and red pigments. 



