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Pararsenolamprite, a new polymorph of native As, from the Mukuno mine, Oita Prefecture, Japan

Published online by Cambridge University Press:  05 July 2018

S. Matsubara ,
R. Miyawaki ,
M. Shimizu  and
T. Yamanaka
S. Matsubara*
Affiliation:
Department of Geology, National Science Museum, 3-23-1 Hyakunincho, Shinjuku, Tokyo 169-0073, Japan
R. Miyawaki
Affiliation:
Department of Geology, National Science Museum, 3-23-1 Hyakunincho, Shinjuku, Tokyo 169-0073, Japan
M. Shimizu
Affiliation:
Department of Earth Sciences, Faculty of Science, Toyama University, Gofuku 3190, Toyama 930-8555, Japan
T. Yamanaka
Affiliation:
Chuo-cho 2-5-20, Nakatsu, Oita 871-0024, Japan
*
*E-mail: [email protected]
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Abstract

Pararsenolamprite, the third polymorph of native As, is found at the Mukuno mine, Oita Prefecture, Japan. It is orthorhombic, Pmn21 or P21nm, a = 3.633(2), b = 10.196(2), c= 10.314(2)Å, Z = 18. The seven strongest lines in the X-ray powder diffraction pattern are: 5.17 (100) (002), 4.60 (24) (012), 3.259 (58) (013), 2.840 (27) (032), 2.580 (22) (004), 2.299 (23) (024), and 1.794 (26) (105). Electron microprobe analysis gives As 91.89, Sb 7.25, S 0.48, total 99.62 wt.% (mean of 8), and lead to the empirical formula, As0.96Sb0.03S0.01. It is lead grey in colour and opaque with metallic lustre and black streak. It is sectile and brittle with perfect cleavage on [001]. The VHN25 is 66–91 kg/mm2, corresponding to 2–2.5 in Mohs' hardness scale. The measured and calculated densities are 5.88(5) g/cm3 and 6.01 g/cm3, respectively. In reflected plane-polarized light in air, it is white with a slightly greenish blue tint. Anisotoropy is strong, dark brown to dark greenish grey. Bireflectance is distinct; parallel to elongation it is creamy; perpendicular to elongation it is brown, grey and green. Internal reflections are absent. The reflectance spectra are tabulated in the text.

Pararsenolamprite occurs as euhedral crystals in close association with arsenic, stibnite and quartz in a Sb-As-Ag-Au-bearing quartz vein cutting altered Neogene andesite from the Mukuno mine. It forms radial or parallel aggregates of bladed cystals up to 0.8 mm in length.

Keywords

pararsenolampritearsenicpolymorphnew mineralMukuno mineX-raychemistryoptical data
Type
Research Article
Information
Mineralogical Magazine , Volume 65 , Issue 6 , December 2001 , pp. 807 - 812
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2001

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References

Clark, A.H. (1970) Arsenolamprite confirmed from the Copiapo area, northern Chile. Mineral. Mag., 37, 732–3.CrossRefGoogle Scholar
Criddle, A.J. and Stanley, C.J. (editors) (1993) Quantitative Data File for Ore Minerals (3rd edition). Chapman & Hall, London.CrossRefGoogle Scholar
Hintze, C. (1886) Über Arsenol amprit. Zeits. Kristallogr. Min., 11, 606–8.Google Scholar
Johan, Z. (1959) Arsenolamprit – die rhombische Modifikation des Arsens aus Cerny Dul (Schwarzental) im Riesengebirge. Chemie der Erde, 20, 71–80.Google Scholar
Kinoshita, K. (editor) (1961) The Ore Deposits of Japan, Vol. 9: the Kyushu District. Asakura Shoten, Tokyo (in Japanese), 219 pp.Google Scholar
Picot, P.and Johan, Z. (1982) Atlas of Ore Minerals. B.R.G.M., Orleans, France, and Elsevier, Amsterdam, The Netherlands, p. 77.Google Scholar
Shimizu, M., Kato, A. and Shiozawa, T. (1986) Sakuraiite: chemical composition and extent of (Zn,Fe)In-for-CuSn substitution. Canad. Mineral. 24, 405–9.Google Scholar
Smith, P.M., Leadbetter, A.J. and Apling, A.J. (1975) The structures of orthorhombic and vitreous arsenic. Phil. Mag., 31, 57–64.CrossRefGoogle Scholar