RARE METALS AND THEIR DESTINATION. 
91 
Gadolinite, Cooglegong. 
Si °2 23.33 
BeO 10.38 (^3.76 Be) 
FeO 12.28 
Ce 2 0 3 2.50 
La 2 0 3 + Di 2 0 , 18.30 
Y 2 O, +Er 2 0 3 33.40 
MgO 69 
Ignition loss .32 
101.20 
Sp. Gr 4.14 
Cadmium. — This metal belongs to the same group 
as beryllium. Whilst it is probably if anything less 
common than thatmetal and is only found in large propor- 
tions in a single very rare mineral, greenockite 
(cadmium sulphide). It, on the other hand, is an 
invariable constituent of zinc ores in quantities rang- 
ing from traces up to 3 per cent. During the smelting 
of zinc ores for the metal, cadmium is readily ob- 
tained as a bye-product and for many years now has been 
put to practical use. The metal is a constituent of many 
fusible alloys, whilst compounds are used in photography, 
in electric cells, and in pigments. It was first detected as 
long ago as 1817 and shortly afterwards obtained in the 
metallic state. 
Cadmium is present in appreciable quantities in the 
blendes of Northampton (W.A.) and probably exists in 
recognisable amounts in other zinc ores in the State. 
Gallium, Indium, Thallium These three metals 
are closely related chemically and are all extremely 
rare. Thallium alone is known to form an essential 
constituent of two very rare minerals, Crookesite 
(selenide of copper, thallium and silver) with 16-19% Tl, 
and Lorandite (a sulpharsenide of thallium) with 59-60% Tl. 
In addition to these thallium has been detected in traces 
in certain specimens of native bismuth, blende, pyrites, 
chalcopyrite, lepidolite, phlogopite and zinnwaldite. Indium 
is known, only in traces, in a number of minerals of widely 
different types, including blende from many localities, most 
iron ores, zinnwaldite, manganotantalite and wolfram. 
Gallium is known as traces (up to 0.002%) in many blendes 
and bauxites, and has also been detected in zinnwaldite 
and phlogopite. 
