Bee hh oi 
te f 
r - 
, 
_ 
300 A. LIVERSIDGE. 
read before the Royal Society of N. 8. Wales, December 2, 1891 
(On some New South Wales and other Minerals, Note No. 6), 
a residue of silica was left. In some cases the residue consisted 
of gelatinous silica, in others of porous quartz resembling the so- 
called geysirite, although before such treatment in most cases 
no quartz was visible nor was. there anything to indicate its 
presence ; the original colour of the stalactites being dark brown ~ 
to lustrous black, as in the typical brown hematite, neither did 
the fracture reveal the presence of silica. 
As the solution went on and the iron oxide was removed the 
stalactites gradually presented an outline in soft transparent 
gelatinous silica, this increases until finally nothing but gelatinous 
silica, or a mixture of it and ordinary silica, was left. No gold 
was visible in the residue, either in the first or second sample 
tried, even after crushing the residue in an agate mortar. 
In a third specimen the silica also was got rid of, by hydro- 
fluoric acid ; on grinding the residue, mainly insoluble iron oxide, 
in an agate mortar, no traces of gold could be seen. This appears 
to indicate that the particular specimens were either free from 
gold, most unlikely, or that owing to its finely divided condition 
it had floated away during the treatment. 
When acted upon by hydrofluoric acid the stalactitic brown 
hematite soon acquired a white appearance, and the various 
fragments became more or less cemented together into rounded 
masses, with numerous vent holes, through which the volatile 
silicon fluoride, acid and steam escaped, so that they looked like 
many a New Zealand Hot Spring in miniature. The quartz is 
rendered soft and friable long before it is removed by the hydro- 
fluoric acid. 
A fourth specimen left a residue of very finely divided gold, 
but without any recognisable crystalline form. A fifth specimen ; 
left the gold as a dull brown powder, j 
. 
A rich specimen of gold quartz from New Caledonia Reef, : 
Queensland, was treated in the same way ‘when a considerable 
