edged crystals to
mammillary-shaped nuggets of wood-tin; from masses of 30 lbs. weight to
a fine sand, like gunpowder, in colour black, brown, grey, yellow,
red, ruby, white, and sometimes a mingling of several colours, it does
require much judgment to know tin.

Stream tin is generally associated with alluvial gold. When such is the
case there is no difficulty in saving the gold if you save the tin, for
the yellow metal is of much greater specific gravity. As the natural tin
is an oxide, and therefore not susceptible to amalgamation, the gold can
be readily separated by means of mercury.

Lode tin sometimes occurs in similar quartz veins to those in which gold
is got, and is occasionally associated with gold. Tin is also found, as
at Eurieowie, in dykes, composed of quartz crystals and large scales
of white mica, traversing the older slates. A similar occurrence
takes place at Mount Shoobridge and at Bynoe Harbour, in the Northern
Territory of South Australia; indeed, one could not readily separate
the stone from these three places if it were mixed. As before stated tin
will never be found far from granite, and that granite must have white
mica as one of its constituents. It is seldom found in the darker
coloured rocks, or in limestone country, but it sometimes occurs in
gneiss, mica schist, and chlorite schist. Numerous other minerals are
at times mistaken for tin, the most common of which are tourmaline or
schorl, garnet, wolfram (which is a tungstate of iron with manganese),
rutile or titanic acid, blackjack or zinc blende, together with
magnetic, titanic, and specular iron in fine grains.

This rough and ready mode of determining whether the ore is tin is by
weight and by scratching or crushing, when, what is called the "streak"
is obtained. The colour of the tin streak is whitey-grey, which, when
once known, is not easily mistaken. The specific gravity is about 7.0.
Wolfram, which is most like it, is a little heavier, from 7.0 to 7.5,
but its streak is red, brown, or blackish-brown. Rutile is much lighter,
4.2, and the streak light-brown; tourmaline is only 3.2. Blackjack is
4.3, and its streak yellowish-white.

I have seen several pounds weight to the dish got in some of the New
South Wales shallow sinking tin-fields, and, as a rule, payable gold was
also present. Fourteen years ago I told Western Australian people, when
on a visit to that colony, that the neighbourhood of the Darling range
would produce rich