320 A. LIVERSIDGE. 
Manganese and magnesium are usually met with, hut they and 
other metals, although specially sought for, were not found in 
this specimen. Dana gives the following extremes :— 
TiO, = 59-20 to 3°55 / 
FeO = 46°53 to 3:26 7 
Fe,0, = 93°63 to 1:20 /% 
ZINCIFEROUS GALENA. 
This mineral was sent to me from Broken Hill as clausthalite, 
the selenide of lead. Before the blowpipe it yielded the reactions 
lead, zine, and sulphur, with a little arsenic, but I could not get 
any reaction for selenium. Decrepitates strongly. It appears to 
occur in nodular masses. 
The mineral, in certain lights has a dull grey colour and scoria- 
ceous appearance, but in other positions the light is reflected 
from it brilliantly with a bluish-grey metallic lustre ; this is due 
to the fact that the surface is covered with minute cubical 
crystals, which have their planes more or less parallel, although 
at different levels ; my specimens only exposed about two square 
inches, but I think it would be found to extend over larger surfaces. 
The effect is something like that of “shot” silk. 
Under a 1” objective, the cubical character of the crystals are 
clearly recognisable, so also are the well -.marked cubical cleavag? 
planes, which have a strong metallic lustre. The mineral appears 
to be homogeneous, and no separate portions of blende were detected 
in it, so that the two sulphides seem to have been deposited t 
gether ; thin tilms of arborescent copper pyrites occur on some ¢ 3 
the surfaces, and within crevices. Sp. gr. at 18°6-72. Itis slightly 
harder than galena. 
The nodules only contain a little zine ; but they have not yet 
been analysed ; On assay they proved to be very rich in gold, 
gave me 5 ozs. 17 dwts. 4 grs. per ton, and 0 oz. 19 dwts. ‘= 
of silver per ton; lead minerals are usually richer in silver than 
in gold. 
The vein stuff gave— 
