707 
I examined them. Nos. 240 and 241 are from the hanging and foot walls respectively of 
gold-reef-bearing granite ; while 212 and 243 are the hanging and foot walls of the 
non-gold-reef -bearing granite. 
Macroscopically, the specimens are grey. No. 240 is permeated by one single 
vein, Jj- inch thick, of a zeolite, which I have often analysed, as per Mineral 
Census, Koyal Society, Queensland, &c. Vide Plate 67, fig. 2. The rock consists 
of quartz, felspars, and hornblende. There is no mica visible with a lens in the hand 
specimens. 
Section . — The texture is granitic, holocrystalline. The richness of the quartzes 
in fluid-inclusions is very great. Planes of these inclusions intersect in various 
directions, and each plane absolutely teems with fluid-inclusions. Under the one-inch 
objective, by oblique reflected light, these inclusions appear beautifully silvery. The 
hornblende is bright green, in part often crumpled, and sometimes reedy (the “schilfige 
hornblende” of Rosenbusch). 
Well-defined crystals of magnetite appear, both included in this hornblende and 
on the margins. The magnetite occurs in the felspars when remote from hornblende, 
and in one case the octahedral crystal is in quartz, having been derived from the horn- 
blende which is contiguous to the quartz, but this is uncommon. All these exhibit 
strong magnetism on jrowdering and washing off the dirt, and using the magnetised 
needle as a means of sepxration. In the neighbourhood of magnetite crystals, 
exquisitely clean-cut apatite crystals aggregate, as is the habit of this mineral. In a 
prism of apatite, '008 inch long and ‘001 inch broad, there is a fluid-enclosure whose 
figure is symmetrical with its host. 
The hornblende is frequently interpenetrated by epidote of a yellowish-green 
tint, polarizing in high coloiir.s, and appearing, by reflected light, very rough on the 
surface, owing to its strong index of refraction. The pleochroism of the hornblende is, 
for rays vibrating parallel to cleavage, bluish green, and at right angles it is yellow. In 
many crystals the cleavages are parallel to an axis of elasticity. 
Felspars . — They are much altered, probably orthoclase amongst them, but not 
certain, and in small quantity. The section must be fairly thin, since the quartzes only 
colour to No. 13 in Newton’s scale, and sometimes layender grey, yet the great majority 
of the felspars are filled with a perfec tly transparent colourless mineral, which is strongly 
coloured between crossed nicols. Prom the fan-shaped groups of some of these invested 
secondary secretions, it is probable that they are epidote. Some may be calcite. In 
No. 241 orthoclase occurs sparingly and between crossed nicols ; the felspar is not 
simultaneously extinguished on turning the stage. A black envelope environs a 
luminous centre, and that is succeeded by a luminous envelope environing a black 
centre {i.e., “ undulose extinction”). 
There is a curious atfinity between the magnetic iron and the apatite. Very 
little difference exists between the hanging-wall of the gold-bearing quartz and the 
hanging-wall of the non-gold-bearing quartz. In No. 242 there appears perhaps less 
hornblende than in No. 210, and what there is, is more crumpled. In No. 243, the 
felspars are less kaolinized, and orthoclase twinned on the Carlsbad type occurs together 
with plagioeJase. One large orthoclase crystal shows signs of zonal structure, and 
exhibits undulose extinction. 
In No. 242 the felspars are most delicately banded, and the hornblende is 
crippled, while the other parts of the slide can be described as in the foregoing eases. 
Some of the felspars in No. 240 appear like picture frames with much beading, slightly 
thrust on one side — i.e., like quadrilateral figures with their opposite sides equal, but all 
their angles not right angles. 
