78 
constituent to be seen in the slide which is difficult to determine. 
It is rather like cordierite and is surrounded by alteration pro- 
ducts, but it has rather a higher index of refraction than 
ordinary cordierite. The rock is moderately fine-grained and in 
parts has quite a pinkish color from the number of garnets 
present. 
XIX. Tremouire Scuist (with GarRNets), Block 10 Mine, 
1,450 ft. Level, Broken Hill, N.S.W. 
This rock is of a schistose character. The hand specimen 
shows tremolite, garnet, and biotite. Quartz and orthoclase are 
present in grains; also garnets, which are cracked, drawn ou‘, 
and are not isotropic, but show anomalous double refraction 
due to strain. Biotite is present, which is rather altered. It is 
also crushed and bent. TZremolite forms a large part of the rock, 
which is a good deal altered, rather friable, and has a sp. gr. 
of 2:94. Muscovite altered to a hydromica is present as a con- 
stituent. The garnets and biotite form layers in the mass. Many 
of the garnets, which are of a light pink color, are quite long 
and rolled out. The rock has undergone great strain. 
The foregoing observations are perhaps little more than cur- 
sory remarks upon the specimens in question, but I hope they 
will suffice to indicate their general composition and character. 
Nos. II., III., IV., VIII, IX., XVI., and XVII. seem to /pre- 
sent the most interesting points. 
In conclusion, I have to acknowledge the kindness of Prof. J. 
W. Judd, F.R.S., who has afforded me, not only the opportunity 
of doing this work in the Geological Laboratory of the Royal 
College of Science, London, but every aid and facility for the 
carrying out of the same. The sections were cut by Mr. F. 
Chapman of the same institution. 
