Flinders is a Dana locality southeast of Melbourne, Victoria, best known for producing large crystals of gmelinite. The basalts are part of the Older Volcanics with a flow near the top of the sequence dated at 42 million years. Zeolites and associated mineralisation occur in vesicles in basalt along the coastline.
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Featured image: Chabazite from Cairns Bay. Photo width is about 7.5mm and a stack of 125 images.
McAndrew and Marsden describe the Older Volcanics in the Flinders area as having olivine present as phenocrysts in a matrix showing flow structure, and consisting of augite, labradorite, iron ore and green glass.
The main mineralised locations in the Flinders area are as follows:
- West Head (at Flinders township)
- Little Bird Rock
- Cairns Bay (previously recorded as Simmons Bay)
- Bushrangers Bay (includes Elephant Rock)
- Cape Schanck
Albite (var: Oligoclase) recorded from West Head.
Biotite: no data available for biotite.
Calcite (including ferroan calcite)
Celestine: Museum of Victoria specimen M39943 listed as on phillipsite and analcime from Cairns Bay.
Chabazite Group (including chabazite-Ca and chabazite-Na)
Cuprite is occasionally found as an alteration of copper crystals.
Digenite: Black platy crystals tentatively identified as digenite (Birch, 1989).
Ferro-Kaersutite: No data available for ferro-kaersutite.
Gmelinite-Na: Often occurs as an intergrowth of chabazite and gmelinite.
Hydroxylapatite occurs as megacrysts in basalt at West Head. See fluorapatite.
Kaersutite: Museum Victoria Mineralogy Collection specimen – black crystals in basalt.
Laumontite: No data available for laumontite.
Magnesite: Reported in 1902 but considered doubtful as no specimens are known to exist (Birch 1989).
Offretite: See erionite-Na
Described by Gottardi and Galli as probably an intergrowth with erionite. But then Passaglia et al determined that practically all “offretite” grown epitaxially on levyne is actually erionite, including those specimens tested from Flinders.
Ranciéite: See Birnessite.
Siderite: Recorded as crystals up to 3mm long with chabazite and montmorillonite.
Unknown Copper Silicate: A transparent green copper silicate (unknown species) coats other copper minerals.
Vivianite: Reported in 1930 but considered doubtful as no specimens are known to exist (Birch 1989).
Zircon: Zircon occurs as phenocrysts in basalt at West Head.
- Birch, W.D. (1975), Chabazite or gmelinite (or both) in basalts from Flinders, Victoria, Australian Mineralogist 1(1).
- Birch, W.D., and Pearson, J.E. (1982), Copper chloride minerals in basalt from Flinders, Victoria. Australian Mineralogist, 1(39).
- Birch, W.D. (1988), Zeolites from Phillip Island and Flinders, Victoria. Mineralogical Record, 19(6).
- Birch, W.D. (1989), Zeolite Minerals of Victoria. The Victorian Mineralogical Society Special Publication No. 2.
- Birch, W.D. and Henry, D. (1993), Phosphate Minerals of Victoria. The Victorian Mineralogical Society Special Publication No. 3.
- CoulsellL, R. (1980), Notes on the zeolite – collecting area of Flinders, Victoria, Australia. Australian Mineralogist, 1(33).
- Gottardi, G. and Galli, E. (1985), Natural Zeolites.
- Henderson, W.A., and Garland, C.M. (1986), Natrolite arches from Simmon’s Bay, Australia. Mineralogical Record, 17(6).
- McAndrew, J. and Marsden, M. (1973), Regional Guide to Victorian Geology.
- Mitchell, S.R. (1930), Zeolites from Flinders. Victorian Naturalist, 47.
- Passaglia, E.,Artioli, G., and Gualtieri, A. (1998), Crystal chemistry of the zeolites erionite and offretite, American Mineralogist, 83.
- Tschernich, R. (1992): Zeolites of the World.