13 
five per cent, potash ore at our very doors, but in tfte same ranges 
are numerous concentrations in the shape of pegmatite veins in 
which the potash is estimated to rise to 7 or 8 per cent., and these 
by hand picking would yield raw material with at least 10 per cent, 
potash. It would be a worthy and profitable research to work out 
in the most complete detail all the chemical properties of this 
felspar (microcline) which in its natural state contains no less than 
12 to 13 per cent, of potash,* with a view of making its potash 
available industrially. In some parts of the world this has been 
done on a small scale in connection with the cement industry by 
acting (3ii the felspar and associated mica at a high temperature 
with lime and a little salt and thus volatilising the potash and 
collecting it as fine dust. As a bye-product in cement making, 
however, the output is limited by the output of cement, being some- 
thing like two per cent, only of the latter, an amount entirely in- 
adequate to supply the demand. The same remarks also apply to 
the English attempts at recovering potash from iron blast furnaces. 
Other methods of utilisation have therefore to be sought. 
At the local pre-war rate for potash every ton of Darling Range 
granite contained 32/6 worth of this indispensable material, a value 
almost doubled at the present time, and likely to be enhanced for 
many years to come. At present rates the average pegmatite 
veins carry 77/- to 88/- worth of potash per ton, and felspar con- 
centrates could readily be obtained from them by hand picking 
which would carry £5 worth per ton. It seems as if the value of the 
contents is not so low as to put out of count the possibility of making 
the treatment of such material a commercial success, and there is 
every possibility of a big reward awaiting the scientist who success- 
fully solves the problem of extracting commercial salts from such 
felspathie ore. Metallurgists in the past have succeeded in over 
coming obst acles just as great and even greater. 
The principal other mineral which had been considered as a 
source of potash was one of a very different type and origin, viz., 
alunite, a basic sulphate of aluminium and potassium. Up till 
11)17 this mineral had only been utilised for the production of 
alum and very few workable deposits of it were known in the world, 
one of them being in New South Wales, but none at all in Western 
Australia. The origin of the mineral was obscure and therefore 
there was no scientific basis upon which to prospect for supplies 
of the mineral. 
One of the first steps towards solving the problem of potash 
■supplies was plainly to determine the mode of origin of alunite. 
A close study of all the known occurrences of the mineral led to the 
conclusion that it owed its origin to the oxidation of pyrites in the 
presence of potash mica or felspar. Plainly, therefore, alunite was 
* By analysis of local felspars. See K.S*S. Sources of industrial potasll in 
Western Australia. G.S. W.A., Bull. 77. Perth, 1919. 
