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Luetheite, Cu2Al2(AsO4)2(OH)H2O, a new mineral from Arizona, compared with chenevixite

Published online by Cambridge University Press:  05 July 2018

S. A. Williams*
Affiliation:
Phelps Dodge Corporation, Douglas, Arizona, U.S.A.

Summary

Luetheite was found at a small prospect in Santa Cruz County, Arizona, as crystals in vugs in rhyolite porphyry. A few specimens were found on the dump, none seen in place. Occurs in silicified porphyry (quartzsericite-alunite) with chenevixite and hematite. Crystals indian blue inclining to greenish, H = 3, Dmeas = 4·28.

Crystals monoclinic 2/m and tabular on a {100}, also a plane of distinct cleavage; other forms are {110}, {140}, {011}. Space group perhaps P21/m with a = 14·743Å, b = 5·093, c = 5·598, β = 101° 49′; strongest lines are 3·498Å (10), 310, 111; 7·208 (7), 200; 2·507 (5), 120, 510. Feebly pleochroic in pale blue in thin section, γ = β > α. Indices are α = 1·752, β = 1·773, γ = 1·796; 2Vγ = 88° (calc.); dispersion is moderate ν > ρ. α ∥ [010], γ: [001] 10° in obtuse β. Duplicate chemical analyses averaged CuO 28·9%, Al2O3 18·4%, As2O5 40·5%, H2O 9·3% giving 2[Cu2Al2 (AsO4)2(OH)4·H2O].

Named for R. D. Luethe, geologist for Phelps Dodge Corporation. Chenevixite from Las Animas, Sonora, analysed to give Cu2Fe2(AsO4)2(OH)4·H2O. Powder data are close to luetheite, and the cell is monoclinic 2/m, probably P21/m, with a = 15·006A, b = 5·189, c = 5·724, β = 102°15. The measured specific gravity is 4·38, Dcale. = 4·59. Crystals tabular on a {100} with a habit very similar to luetheite. Indices are α = 1·92 , β = 1·96, γ = 2·04, 2Vγcale. = 75°; α ∥ [100], γ nearly ∥ [001].

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1977

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References

de Bournon, (J. L.), 1801. Philos. Trans. R. Soc, part 2, 169–92.Google Scholar
Chenevix, (R.), 1801. Ibid. 193-240.Google Scholar
Claringbull, (G. F.), Hey, (M. H.), and Davis, (R. J.), 1959. Mineral. Mag. 32, 1–5.Google Scholar
Hillebrand, (W. F.), 1883. Proc. Colorado Sci. Soc. 1, 112–19.Google Scholar
Mackenzie, (G. S.), 1885. Mineral. Mag. 6, 181-2.Google Scholar
Pallas, (P. S.), 1794. Voyages du Professeur Pallas, dans plusieurs provinces de Vempire de Russie, 3, Paris (Maraday).Google Scholar
Pierrot, (R.), and Walter, (J.), 1961. Bull. Soc.fr. Mineral. Cristallogr. 84, 23.Google Scholar
Pisani, (F.), 1866. C. R. Acad. Sci. Paris, 62, 690–2.Google Scholar
Smith, (G.), 1926. Mineral. Res. N.S.W., no. 34, 80.Google Scholar
Villarroel, (H.), 1964. Bull. Soc. fr. Mineral. Cristallogr. 87, 626–8.Google Scholar