Sugilite in manganese silicate rocks from the Hoskins mine and Woods mine, New South Wales, Australia

Abstract

Sugilite relatively rich in manganese has been found at two new localities, the Hoskins and Woods mines in New South Wales, Australia. The occurrences are in manganese-rich silicate rocks of middle to upper greenschist facies (Hoskins mine) and hornblende hornfels facies (Woods mine). Coexisting minerals are members of the namansilite-aegirine and pectolite-serandite series, Mn-rich alkali amphiboles, alkali feldspar, braunite, rhodonite, tephroite, albite, microcline, norrishite, witherite, manganoan calcite, quartz, and several unidentified minerals. Woods mine sugilite is colour-zoned with pale mauve cores and colourless rims, whereas Hoskins mine sugilite is only weakly colour-zoned and pink to mauve. Within single samples, the chemical compositions of sugilite from both localities show wide ranges in A1 contents and less variable ranges of Fe and Mn, similar to trends in sugilite from other localities. The refractive indices and cell dimensions tend to show systematic increases progressing from Al-rich to FeMn-rich. The formation of the sugilite is controlled by the high alkali (especially Li) and manganese contents of the country rock, reflected in the occurrences of coexisting high alkali-and manganesebearing minerals, and by high fo2 conditions.

Non-pegmatitic Deposits of Beryllium: Mineralogy, Geology, Phase Equilibria and Origin

“…Similar rocks at Franklin, New Jersey (Palache and Bauer 1930) may have a granitic source for their Be. Miscellaneous locations include helvite with Mn-rich jaspers in the Pyrenees Mountains (Ragu 1994b), bergslagite and other Be enrichments with Mn-Fe oxide layers in Switzerland (Graeser 1998;Brugger and Gieré 2000), and milarite with Mn oxide deposits in New South Wales (Kawachi et al 1994). Mn-Fe-oxide-rich hot spring deposits in Nevada (Golconda, Sodaville) contain up to 60 ppm Be (160 ppm BeO) along with W and other metals (Warner et al 1959).…”

Noélbensonite, a new BaMn silicate of the lawsonite structure type, from Woods mine, New South Wales, Australia

“…THE Woods mine 30 km NNE of Tamworth, New South Wales, Australia, has been worked for ornamental rhodonite, and contains a range of other manganese-rich minerals including serandite (Kawachi, 1987), NaMn amphibole (Kawachi, 1991), namansilite and manganian aegirine (Kawachi and Coombs, 1993), sugilite (Kawachi et al, 1994), braunite, hausmannite, tephroite, rhodochrosite, and unidentified phases as well as quartz, albite, K-feldspar, barite, and apatite. In this paper we describe the BaMn 3 § analogue of lawsonite, the SrMn 3 § analogue of which, hennomartinite, was recently described from the Wessels mine, Kalahari, South Africa (Armbruster et al, 1992(Armbruster et al, , 1993.…”