24 ECONOMICAL MINERALOGY. 



Stated, as a sufficient evidence of the value of this ore, that in the island of Elba it has been 

 worked since the time of the Romans, and that the iron obtained firom it has always been 

 held in the highest estimation. 



Geological situation. The specular oxide of iron is usually found in beds and veins in 

 the primary or the older transition rocks. It is not met with in any abundance in the secondary 

 formations. 



According to Dr. Emmons, this ore is found in the State of New- York in two geological 

 situations. In the first, it is associated with primary limestone, as occurs in many cases in 

 the town of Edwards, St. Lawrence county ; in the second, it has gneiss or some other 

 primary rock below and the Potsdam sandstone above, as in the Kearney and Parish mines 

 in the same county.* 



As I intend, under the name of Specular Oxide of Iron, to describe localities of ores which 

 are often known by other names, it may be useful here to notice the different varieties, now 

 included imder the present species. 



Common Specular Iron, has a metallic appearance, is of a steel-grey or iron-black colour, 

 and frequently occurs in the form of crystals. Characteristic specimens are found in several 

 deposits in St. Lawrence county. 



Micaceous Specular Iron. This resembles the preceding in its colour, but is composed of 

 thin shining laminae, or scales, applied to each other. Its powder is a dark red. 



Red Iron Stone, is destitute of a metallic appearance, and includes red hematite, found in 

 masses, stalactites, kidney-form balls, &c., and having a brownish red colour and fibrous 

 structure ; the compact and ochrey red iron ores, which are massive and have a compact 

 texture ; and iron froth, composed of scaly friable parts, which soil strongly, and have a 

 colour between cherry and brownish red. To these may be added the Lenticular Clay Iron 

 ore, so abimdant in the western part of the State. 



Geographical range. This ore is found almost exclusively in the northern and western 

 parts of the State. In the county of St. Lawrence it takes the place of the magnetic oxide, 

 while it becomes less abundant as we proceed to the eastern boundary of the State. Again, 

 in the counties bordering on the Erie canal, the lenticular variety is met with in layers of 

 various degrees of thickness, from Herkimer to Monroe. 



I shall now describe some of the most important deposits of this ore. 



Essex County. Near the summit of Mount Defiance, in Ticonderoga, is a naiTOw vein 

 of the red hematite in a granitic rock. It is associated with quartz, and sometimes passes 

 into the variety known by the name of jaspery iron. It is peroxide of iron mixed, and chemi- 

 cally combined, with variable proportions of silica. It is used both as a paint, and as an ore 

 for furnishing metallic iron. About thirty tons of the mineral are said to have been obtained 

 from this locality, but the difficulty of access renders it almost valueless. 



* New- York Geohgical Reports, 1840. 



