Broken Hill Mines – the Story – Chapter 5: Our Mineral Heritage

Our mineral heritage from the Broken Hill lode is the 300 plus minerals that occurred in the ore, the gangue and the oxidised zone.

First, the major ore minerals were galena and sphalerite, which comprised the bulk of the lenses in the lode. Additionally, the ore contained many minor minerals, including chalcopyrite, arsenopyrite, loellingite, pyrrhotite, cobaltite, tetrahedrite, albandite, stannite, bournonite and many others.

Secondly, the gangue comprised the non-sulphide minerals that were intimately associated with the ore minerals. A few of those minerals were quartz, spessartine, gahnite, rhodonite, fluorite, pyrosmalite, inesite, bustamite, hedenbergite, calcite, feldspar and apatite.

Thirdly, the secondary minerals in the oxidised zone were those formed by weathering of that part of the ore body exposed by erosion and not themselves washed away by the erosion processes. These minerals were not, of course, present in the original lode. Thus, the secondary minerals include carbonates – cerussite, azurite, smithsonite; sulphates – anglesite, barite; phosphates – pyromorphite; chlorides – embolite; arsenical compounds – mimetite, scorodite; tungstates – stolzite, raspite; metals – copper, silver, lead, antimony; along with hundreds more with various chemistries. All these minerals are listed and described in Minerals of Broken Hill, Editions 1 and 2. They occurred both singly and in stunning associations as many thousands of marvellous specimens. Of course, most of these went straight into crushers and blast furnaces, but many were saved to satisfy, at least partially, the demands of multitudes of collectors. For example, the proprietor of the Duke of Cornwall hotel encouraged miners to bring him good specimens in their tea billies, and he would replace them with draft beer. What is left today can be only a small fraction of the material dug from the mines, but nevertheless, there are many superb specimens in personal and institutional collections.