RHODES! AN MINERALS. 62 I 



Rhodesian Minerals. — The Bulletin of the Imperial 

 Institute* publishes a short account of the mineral resources of 

 Rhodesia, together with a selection of reports on some of the 

 samples. Antimony sulphide carrying gold and silver occurs in 

 several localities, and the output of antimony from the Gwelo 

 district in 1916 amounted to 38 tons. Arsenical ores are treated 

 for their gold and silver in various districts, but only 76 tons 

 of arsenic is recorded as having been recovered. The output 

 of asbestos has increased from 290 tons in 1913 to over 9,500 

 tons in 191 7. Granular harytes occurs in extensive deposits 

 within two miles of Gado siding. Bismuth minerals occur in the 

 Mazoe district and elsewhere. Of chrome ore Rhodesia is now 

 the world's largest producer. The output of coal from the 

 Wankie colliery was nearly half a million tons in 1916, and, 

 in addition, 99,000 tons were converted into coke. Nearh^ 4,000 

 tons of copper were produced in 1917, diiefly from the Falcon 

 mine in the Umvuma district. Corundum of gem c|uality, in the 

 form of ruby, amethyst, and sapphire, is found in the Somabula 

 gem-bearing gravels, 80 miles north-east of Bulawayo. These 

 gravels also yield diamond, blue and white topaz, and other 

 stones. There are pipes of kimberlite near Bembesi in which 

 diamonds occur. Gold furnishes about 80 per cent, by value of 

 Rhodesia's mineral output. Graphite, usually imijure, occurs at a 

 number of places, iron ores are widely distributed, and galena is a 

 common mineral in the gold-bearing lodes. Limestones are found 

 in many districts, that at Broken Hill containing lead, zinc, and 

 vanadium minerals ; magnesite is reported from three or four 

 localities ; and manganese ore occurs near the Somabula diamond 

 workings. Molybdenite occurs in the Salisbury, Bulawayo, Mazoe 

 and other districts. Good-sized masses of muscovite occur in the 

 Tuli district, while lepidolite abounds near Salisbury. Nickel 

 occurs in small quantities in various parts of Rhodesia. Triplite, a 

 fluor-phosphate of manganese and iron, is found in considerable 

 quantities, associated with bismuth minerals. A platiniferous 

 deposit has been discovered in the norite dyke in the Gwelo 

 district. Potassium nitrate is recorded from Belingwe, and 

 potassium sulphate, in general composition resembling the Stass- 

 furt potash-magnesia salts, is said to occur in banded ironstone. 

 Silver occurs in various forms, and tin is found as tinstone, and 

 in stanniferous pegmatites. Zinc blende is known in a number 

 of localities, and vanadium is associated with the zinc and lead 

 ores of Broken Hill. Wolframite is found near Bulawayo, some- 

 times in masses of 2 cwt. Tantalite occurs in coarse radiating 

 masses in the Victoria tin field. Talc and steatite are of frequent 

 occurrence in the great intrusion of ultra-basic rocks. 



*16 [4], pp. 456-476 (1918); 



