A RARE COPPER MINERAL. 



By Prof. Paul Daniel Hahn, M.A., Ph.D. 



None of the heavy metals form a larger number of combina- 

 tion, which are met with in Nature than the well-defined minerals 

 Copper and Lead. Even an ordinary student's Handbook of 

 Mineralogy enumerates about 50 different minerals of which Copper 

 is an integral constituent. This is mainly due to the property of 

 Copper of readily forming under favourable conditions an oxide of 

 a strongly basic character, which freely combines with acidic 

 radicals formed in the disintegration and chiefly in the oxidation 

 of the ores of Copper and of other metals. Of the numerous 

 Copper minerals only a comparatively small number occur in large 

 quantities in ore deposits, and the student of Metallurgy has rarely 

 to pay attention to more than 12 or 15 of these Copper minerals. 

 The Mineralogist and the student of Mineral-Chemistry, however, 

 include all the numerous combinations in their studies, and the 

 rare mineral naturally attracts their special attention. 



The common Copper minerals, such as the Carbonates and 

 Sulphides, have been observed in South Africa from the Knysna 

 in the South to Broken Hill in the North, and from Damaraland 

 in the West to Zululand in the East. 



Already in the time of Governor Van der Stel an expedition 

 was sent to Little Namaqualand to explore the Copper ores of 

 that region, but only in the middle of the last century Copper 

 ores were mined in the Western part of South Africa near the 

 Coast. In recent times the Germans Tiave started Copper mining 

 in Damaraland and export at present more Copper via Swakop- 

 mund than we do from Little Namaqualand via Port Nolloth. 



The Copper mines in Southern and Northern Rhodesia are now 

 being developed, and we may expect that before long these mines 

 in Central South Africa will also be productive of the red metal. 

 The demand for Copper is constantly rising in connection with 

 the development of all electro-technical industries, and it is not 

 unreasonable to expect that Copper smelting and Conper refining 

 will soon be established in those parts of South Africa, in which 

 coal and water power is available at no great distance from the 

 Copper ore deposits. 



At Broken Hill and at the Tsumeb and Otavi Mines in 

 Damaraland very beautiful Copper minerals, such as Malachite 

 and Azurite, and exquisite pseudomorphous formations of Mala- 

 chite and Azurite, have been discovered, the sight of which must 

 gladden the heart of every true mineralogist. But the most in- 

 teresting mineral which has been found in the Damaraland mines 

 is Dioptase, one of the rarest, if not the rarest of all Copper 

 minerals. 



This beautiful mineral first became known towards the end of 

 the 18th Century, when a few small specimens were brought to 

 St. Petersburg from Mount Altyn-Tiibe, in the Khirgas-Steppes. 

 These specimens were first described as Errierald, but Vauquelin, 

 the famous chemist, the discoverer of Chromium, proved that the 



