62 THE PROSPECTOR'S HANDBOOK. 



IRON. 



When heated before the blowpipe some of the ores are 

 infusible, while most become, if not naturally so, attractable 

 by the magnet. When the test is not destroyed by the 

 presence of other metals, iron in a mineral when heated 

 with borax on a platinum wire in the inner flame produces 

 a bottle-green glass ; in the outer, a dark red, when hot ; a 

 light red, when cold. 



Iron Pyrites (mundic). 



Crystallization usually cubical ; also octahedral, &c. 



Lustre frequently bright metallic. 



Colour yellow of different shades. 



Streak brownish black. 



H. -6 to 6-5 ; S.G. 4-5 to 5. 



Composition about half iron and half sulphur. 



Strikes fire with steel, and has slightly peculiar smell 

 when broken. If heated before B.F., sulphur fumes are 

 given off, and eventually a globule of metal, attractable by 

 the magnet, is obtained. The powder of iron pyrites is very 

 slowly soluble in nitric acid. This ore carries gold in either 

 a small or great quantity, and is generally to be found in 

 gold-bearing and other lodes, oxide of iron, colouring the 

 quartz brownish, representing at the surface the decomposed 

 iron pyrites such as exists in the vein deeper down. 



The mineral is often mistaken for copper pyrites and 

 sometimes for gold, but its being too hard to be cut by a 

 knife is a distinguishing test. Iron pyrites is not employed 

 for the extraction of iron ; it is the chief mineral, however, 

 from which sulphuric acid is obtained. In Spain are very 

 rich deposits from which most of the ore brought to England 

 is mined, although the Coal measures of this country aro 

 productive. 



Magnetic Pyrites. 



Crystallization hexagonal prisms, &c. 



Colour between copper red and yellow, inclining to 



bronze. 

 Streak greyish black. 



