250 J. MILNE CURRAN. 
south, at Nimby, another basalt dyke is seen to be the matrix 
of the red garnets. This dyke can be traced from a point just 
in front of Mr. Edward Fallon’s house in a southerly direction 
for a mile or more. In that distance the character of the stone 
changes somewhat. At the south end the basalt stands out in 
little hillocks, and is not in any way remarkable in hand speci- 
mens. Further north phenocrysts of a dark lustrous mineral 
show in the stone. These are sometimes one inch in diameter, 
giving the rock quite a distinctive appearance. Through the 
courtesy of Mr. John Burke, s.p., of Murrumburrah, I was 
able to sink a few feet through the rock. Some interesting 
specimens were thus secured. I had the satisfaction of finding 
the blood-red garnet in situ. In most cases the garnet was asso- 
ciated with common olivine, which occured in the basalt in nests 
measuring half an inch across. The olivine was granular, and of 
various shades in the same mass, sometimes of a rich sapphire 
green of so fine a colour as to rise to the dignity of chrysolite. 
As regards colour this chrysolite is perfect, but unfortunately no 
Specimens of any size were found. It was not easy to procure 
specimens pure enough for analysis, indeed the results of the 
analyses made vary so much that I am not prepared to give them 
here. The stones show no cleavage, are dark between crossed 
nicols, and are fusible before the blowpipe. Specific gravity 3°78. 
The large lustrous black phenocrysts in this basalt were corroded 
and rounded, and had evidently floated some time in the molten 
magma. These were found to be pyroxenes, closely allied to augite- 
The following is an analysis of the pyroxene with an example 
of a St. Vincent augite for comparison. This last is taken from — 
Dana’s “System of Mineralogy,” p. 361, edition 1892. 
Pyroxene from near Harden. Augite, St. Vincent. 
i 49:80 ves 45:14 
Al,O, 9:90 8:15 
Fe,0O, 8:64 5°25 
CaO 15:80 oh aa 19:57 
MgO 15°86 nes as 14°76 
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