72 
A very small amount of orthoclase is also present 
in some specimens of the rock, occurring as a subordinate 
accessory constituent. 
Nepheline is quite subordinate to the feldspar in 
amount. It is sometimes quite fresh, but at other 
times is found more or less completely altered to a mineral 
which is either muscovite or kaolin. The nepheline is 
allotriomorphic and occurs chiefly in the corners between 
the larger crystals of feldspar and other minerals, and is 
penetrated by them. It is especially abundant in those 
portions of the rock which are rich in the dark coloured 
constituents. When occurring in this manner it appears, 
with the sodalite, to have been the last constituent of the 
rock to crystallize out. It is usually much more abundant 
than the sodalite. The nepheline also occurs in places as 
as irregular-shaped lath-like inclusions in the feldspar. 
Sodalite is usually, although not invariably, present. 
It strongly resembles the nepheline in appearance and 
shows the same alteration product. Like the nepheline, it 
occurs either in the spaces between the other minerals, 
cementing them together, or as inclusions in the feldspars. 
The abundance of apatite is a distinct feature in this 
as in similar rocks occurring elsewhere. It is always 
present and was the first constituent to crystallize out, 
being found in the form of perfect hexagonal prisms with 
double pyramidal terminations imbedded in the iron 
ore. It also occurs in the sphene as well as in the iron- 
magnesia constituents, in the nepheline, and also, although 
much less frequently, in the feldspar. Its large amount 
is shown by the high percentage of phosphoric acid in the 
analysis of the rock, I-23 per cent. Another specimen 
of the rock in which the phosphoric acid was determined 
by Dr. B. J. Harrington gave 1-01 per cent.) ieee 
figures represent 2-79 per cent. and 2-35 per cent. of 
apatite, respectively. It is usually somewhat turbid 
from the presence of minute dust-like inclusions. 
Maegnetite occurs chiefly inclosed in the iron-magnesia 
constituents, but is occasionally found in the feldspar. 
It is usually allotriomorphic, but occasionally presents 
an approximation to definite crystalline outline. As 
shown by the calculation of the analysis of the rock, this 
iron ore contains a considerable percentage of titanic acid. 
Sphene is not found in more than one half of the speci-. 
mens examined. When present it is not very abundant. 
