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Wagnerite with isokite from the Benson Mines, west-central Adirondack Highlands, New York

Published online by Cambridge University Press:  05 July 2018

Howard W. Jaffe ,
Leo M. Hall  and
Howard T. Evans Jr.
Howard W. Jaffe
Affiliation:
Department of Geology and Geography, University of Massachusetts, Amherst, Massachusetts 01003
Leo M. Hall
Affiliation:
Department of Geology and Geography, University of Massachusetts, Amherst, Massachusetts 01003
Howard T. Evans Jr.
Affiliation:
U.S. Geological Survey, National Center 959 Reston, Virginia 22092, U.S.A.
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Abstract

The rare fluophosphate minerals wagnerite, ideally Mg2(PO4)F, and isokite, ideally CaMg(PO4)F, are intimately associated with magnetite-hematite deposits in sillimanite-, garnet-, and pyroxene-rich paragneisses and migmatites at the Benson Mines, near Star Lake in the west-central Adirondack Highlands of New York State. Coarsely crystalline wagnerite occurs in lenticular masses, typically 4 × 8 cm, delineated by sharply cross-cutting, sinuous, 2 cm-wide veins of fine-grained, fibrous to platy isokite and granular fluorapatite. These also penetrate transverse fractures across wagnerite lenses. Isokite formed from the introduction of Ca- and O-rich hydrothermal solutions into wagnerite. Both minerals are monoclinic: wagnerite crystallises in space group P21/a with a = 11.945, b = 12.717, c = 9.70 Å, β = 108.18°, V = 1400.2 Å3, D(calc) = 3.291 g/cm3 for Z = 16; isokite crystallises in space group A2/a with a = 6.909, b = 8.746, c = 6.518 Å, β = 112.20°, V = 364.7 Å3, D(calc) = 3.248 for Z = 4. Optical properties for wagnerite are: α = 1.5845, β = 1.5875, γ = 1.6010, 2V = 51°(calc.) disp = r < v weak, absorption α < β > γ with α = col., β = pale yel., γ = v. pale yel. For isokite only a mean index of refraction, n = 1.598, could be measured. Wet chemical analysis of wagnerite containing a calculated 11.4% of isokite as fine lamellae, gave the formula:

Keywords

wagneriteisokiteBenson minesAdirondack HighlandsGrenville ProvinceNew York
Type
Mineralogy
Information
Mineralogical Magazine , Volume 56 , Issue 383 , June 1992 , pp. 227 - 233
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1992

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Footnotes

*

Present address: R.R.1 Box 540 Range Road, Underhill, Vermont 05489-9402, U.S.A.

†

Deceased

References

Buddington, A. F. (1977) Guidebook for field trips: Petrology and mineral deposits, northwestern and northern Adirondack Area. A. F. Buddington, Princeton University, pp. 35–41.Google Scholar
Coda, A., Giuseppetti, G., and Tadini, C. (1967) The crystal structure of wagnerite. AttiAcc. Naz. Lincei., Serie VIII, 43, 211-24.Google Scholar
Deans, T. and McConnell, J. D. C. (1955) Isokite, CaMgPO4F, a new mineral from Northern Rhodesia. Mineral. Mag., 30, 681–90.Google Scholar
Fisher, D. J. (1957) Isokite and triplite from Bohemia. Ibid., 31, 587-602.Google Scholar
Fontan, F. (1981) La magniotriplite ferrifére du massif des Albères (Pyrénées-Orientales, France). Une nouvelle variété. Bull. Mineral., 104, 672–5.Google Scholar
Ginzburg, A. I., Kruglova, N. A., and Moleva, V. A. (1951) Magniotriplite- —a new mineral of the triplite group. Dokl. Akad. Nauk. SSSR, 76, 97–100.(in Russian).Google Scholar
Hegemann, F. and Steinmetz, H. (1927) Die Mineral- gange yon Werfen, im Salzkammergut. Centralblatt Mineral. Geol. Pal., 1927A, 45-56.Google Scholar
Henriques, Å. (1957) An iron-rich wagnerite, formerly named talktriplite, Hhllsjrberget (Hållsjöberget), Sweden. Arkiv Mineral. Geol., 2, 149-53.Google Scholar
Irouschek, A. and Armbruster, Th. (1984) Hydroxyl- haltiger Wagnerit aus dem Ambra (Tessin, Schweiz). Fort. Mineral., 62, Beiheft 1, 109-10.Google Scholar
Jaffe, H. W. (1988) Crystal Chemistry and Refractivity, Cambridge University Press, Cambridge and New York; ch. 11, pp. 118-46.Google Scholar
Novák, M. and Povondra, P. (1984) Wagnerite from Skřinářov, central Czechoslovakia. Neues Jahrb. Mineral., Mh., 536-42.Google Scholar
Palmer, D. F. (1970) Geology and ore deposits near Benson Mines, New York. Econ. Geol., 65, 31–9.CrossRefGoogle Scholar
Propach, C. (1976) Wagnerit von Bodenmais (Bayer-ischer Wald). Neues Jahrb. Mineral., Mh., 157-9.Google Scholar
Sheridan, D. M., Marsh, S. P., Mrose, M. E., and Taylor, R. B. (1976) Mineralogy and geology of the wagnerite occurrence on Santa Fe Mountain, Front Range, Colorado. U.S. Geol. Survey Prof. Paper, 955, 1–23.Google Scholar
Speer, J. A. and Gibbs, G. V. (1976) The crystal structure of synthetic titanite, CaTiO[SiO4], and the domain textures of natural titanites. Am. Mineral., 61, 238-47.Google Scholar
Tadini, C. (1981) Magniotriplite: its crystal structure and relation to the triplite-triploidite group. Bull. Mineral., 104, 677–80.Google Scholar
Takenouchi, S. (1971) Hydrothermal synthesis and consideration of the genesis of malayaite. Mineral. Deposita, 6, 335–47.CrossRefGoogle Scholar
Taylor, M. and Brown, G. E. (1976) High temperature structural study of the P21/a <-> A2/a phase transition in synthetic titanite, CaTiOSiO4. Am. Mineral., 61, 435–47.+A2/a+phase+transition+in+synthetic+titanite,+CaTiOSiO4.+Am.+Mineral.,+61,+435–47.>Google Scholar
Waldrop, L. (1969) The crystal structure of triplite, (Mn,Fe)aFPO4. Zeit. Krist., 130, 1–14.CrossRefGoogle Scholar