The Magnet Mine, located at Magnet, a settlement that once existed 10km West of Waratah (30 km N of Dundas), was the largest silver-lead-zinc mine in the area, producing 27,000 tons of lead and 184 tons of silver from 1877 to 1940 (Haupt et al., 1995). The tailings were also reworked for 20-30,000 tons of zinc in the 1970’s.
The main siderite-dolomite-sulphide vein lies at the contact of a Cambrian mafic/ultramafic body called the Magnet Dyke (now mostly altered to an amphibolite), with Cambrian sedimentary host rocks (Groves and Solomon, 1964). The host rock near the lode contains relict chromite crystals in a matrix of chromian muscovite (fuchsite) and dolomite (Haupt et al., 1995). The primary lode is a strongly banded, breccia-style vein which comprises mostly sulphides and carbonates.
Although this crocoite-producing mine was discovered well before the Heazlewood mine, the mineral was not reported until after the find at the Heazlewood. Entangled masses of fine prismatic crocoite crystals to 5 cm and longer were found in the manganiferous gossan at Magnet. Small, loose, perfectly terminated crystals were less frequently found and in some vughs it was associated with yellow cerussite or mimetite (colourless to yellow or red).
The gossan is still exposed in a small open-cut and the site is now a public fossicking reserve. Good specimens can still be found with some work, especially yellow and white cerussite.
References:
- Dana 6: App. 2 (1909), by Dana, E.S., and W.E. Ford: 14.
- Palache, C., Berman, H. & Frondel, C. (1944), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, 7th. edition, Volume I: 477.
- Groves, D.I. and Solomon, M. (1964) The geology of the Mt Bischoff district. Papers and Proceedings of the Royal Society of Tasmania, 98, 1-22.
- Haupt, J., Bottrill, R.S. and Sorrell, S.P. (1995) The minerals of the Magnet Mine, Tasmania. Australian Journal of Mineralogy, 1(1), 3-19.
