8 
ECONOMICAL MINERALOGY. 
McFarlane tract. It has not been extensively wrought, although there are evidences of an 
abundant deposit. The ore is strongly magnetic, possesses polarity, and is remarkable for the 
ease with which it cleaves in the direction of the primary octahedron. Large cleavage crystals 
may be obtained. Associated with the ore are mica, hornblende, pyroxene, magnetic and 
common iron pyrites. 
The following are the results of my analysis of a specimen of this ore, which had the 
octahedral cleavage and an iron black colour: 
Protoxide and peroxide of iron,. 96.50 
Silica and alumina,_. ._.__ 3.50 
Forsliee Mine. This is an extensive bed of magnetic iron ore, about a quarter of a mile 
southwest of the O’Niel Mine. The whole hill, which is more than a quarter of a mile in 
length and nearly as much in width, appears to consist of alternate layers of rock and ore, 
the latter forming a large proportion. The general direction of the deposit is nearly north 
and south. Some of the layers of ore have a compact structure, while others are made up of 
what is called shot ore , often quite free from iron pyrites. Rarely it is found crystallized in 
the form of octahedrons. In some parts of the mine, the ore has a cavernous or cellular 
structure, as if some of the original constituents had undergone decomposition and been dis¬ 
solved out. This form of ore passes into an earthy oxide of iron, having a dark brown colour, 
and closely resembling umber. 
The following is the composition of the cellular variety of the magnetic oxide of iron from 
this mine : 
Protoxide of iron,__ 44.10 
Peroxide of iron,...52.75 
Silica and alumina,...... 3.15 
Oxides of titanium and manganese,._ traces. 
The constituents of the umber, according to my analysis, are as follows, viz : 
Peroxide of iron, . 68.00 
Peroxide of manganese,. 8.50 
Silica and alumina,... 6.50 
Water,. ... 17.00 
The last, therefore, is a hydrous peroxide of iron, and is undoubtedly the result of the 
decomposition of iron pyrites. 
Associated with the iron ore at this mine, are delicate veins of amianthus, red garnet, brown 
tremolite, calcareous spar, serpentine and mica. 
It may be added, that the ore from the Forshee Mine is highly valued by the iron masters 
in this part of the State, especially those portions of it which are granular and cavernous. 
The latter variety is sufficiently free from iron pyrites to be used without the preliminary 
operation of roasting. 
