Hostname: page-component-8448b6f56d-jr42d Total loading time: 0 Render date: 2024-04-18T07:58:47.151Z Has data issue: false hasContentIssue false
  • English
  • Français

Anorpiment, As2S3, the triclinic dimorph of orpiment

Published online by Cambridge University Press:  05 July 2018

A. R. Kampf ,
R. T. Downs ,
R. M. Housley ,
R. A. Jenkins  and
J. Hyršl
A. R. Kampf*
Affiliation:
Mineral Sciences Department, Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, California 90007, USA
R. T. Downs
Affiliation:
Department of Geosciences, University of Arizona, Tucson, Arizona 85721-0077, USA
R. M. Housley
Affiliation:
Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
R. A. Jenkins
Affiliation:
4521 N. Via Madre, Tucson, AZ 85749, USA
J. Hyršl
Affiliation:
Ke kurtum 383, 142 00 Praha 4, Czech Republic
*
*E-mail: akampf@nhm.org
Get access Rights & Permissions [Opens in a new window]

Abstract

The new mineral anorpiment, As2S3, the triclinic dimorph of orpiment, has space group PI and cell parameters a = 5.7577(2), b = 8.7169(3), c = 10.2682(7) Å, α = 78.152(7), β = 75.817(7), γ = 89.861(6)°, V = 488.38(4) Å3 and Z = 4. It occurs at the Palomo mine, Castrovirreyna Province. Huancavelica Department, Peru. It is a low-temperature hydrothermal mineral associated with dufrenoysite, muscovite, orpiment, pyrite and realgar. It occurs in drusy crusts of wedge-shaped, transparent, greenish yellow crystals. The streak is yellow. The lustre is resinous on crystal faces, but pearly on cleavage surfaces. The Mohs hardness is about VA. The mineral is sectile with an irregular fracture and one perfect and easy cleavage on ﹛001﹜. The measured and calculated densities are 3.33 and 3.321 g cm–3, respectively. All indices of refraction are greater than 2. The mineral is optically biaxial (—) with 2V = 35—40° and no observed dispersion. The acute bisectrix (X) is approximately perpendicular to the ﹛001﹜ cleavage. Electron microprobe analyses yielded the averages and ranges in wt.%: As 58.21 (57.74–59.03), S 38.72 (38.33–39.00), total 96.94 (96.07–97.75), providing the empirical formula (based on 5 atoms) As1.96S3.04. The strongest powder X-ray diffraction lines are [d (hkl) I] 4.867(002) 97, 4.519 (110,11̄1) 77, 3.702 (1̄1̄1) 46, 3.609 (022,11̄2) 82, 2.880(201,02̄2,1̄2̄1,023) 75, 2.552 (1̄13,1̄31,132) 100, 2.469 (114,130,13̄1) 96. The structure of anorpiment [R1 = 0.021 for 1484 reflections with F0 > 4σ(F)] consists of layers of covalently bonded As and S atoms. Each S atom bonds to two As atoms at As—S—As angles between 100.45 and 104.15°. Each As atom is strongly bonded to three S atoms at S—As—S angles between 91.28 and 103.59°, forming an AsS3 pyramid with As at its apex. The As—S linkages within the layers form rings of six AsS3 pyramids. Interlayer bonding forces are interpreted as van der Waals. The structure of anorpiment is similar to that of orpiment in that it is composed of layers of As2S3 macromolecules, but arranged in a different stacking sequence.

Keywords

anorpimentnew mineralcrystal structureorpimentarsenic sulphidevan der Waals forcesPalomo minePeru
Type
Research Article
Information
Mineralogical Magazine , Volume 75 , Issue 6 , December 2011 , pp. 2857 - 2867
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2011

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Besson, J.M., Cernogora, J. and Zallen, R. (1980) Effect of pressure on optical properties of crystalline As2S3 . Physical Review B, 22, 3866-3876.CrossRefGoogle Scholar
Burla, M.C., Caliandro, R., Camalli, M., Carrozzini, B., Cascarano, G.L., De Caro, L., Giacovazzo, C., Polidori, G. and Spagna, R. (2005) SIR2004: an improved tool for crystal structure determination and refinement. Journal of Applied Crystallography, 38, 381-388.CrossRefGoogle Scholar
Burns, P.C. and Percival, J.B. (2001) Alacranite, As4S4: a new occurrence, new formula, and determination of the crystal structure. The Canadian Mineralogist, 39, 809-818.CrossRefGoogle Scholar
Crowley, J.A., Currier, R.H. and Szenics, T. (1997) Mines and minerals of Peru. Mineralogical Record, 28, 1-98.Google Scholar
Devaud, G., Aziz, M.J. and Turnbull, D. (1989) Highpressure crystallization kinetics of As2S3 . Journal of Non-Crystalline Solids, 109, 121-128.CrossRefGoogle Scholar
Downs, R.T., Gibbs, G.V., Boisen, M.B., Jr. and Rosso, K.M. (2002) A comparison of procrystal and ab initio representations of the electron-density distributions of minerals. Physics and Chemistry of Minerals, 29, 369-385.CrossRefGoogle Scholar
Espeau, P., Tamarit, J.L., Barrio, M., López, D.ó., Perrin, M.A., Allouchi, H. and Céolin, R. (2006) Solid state studies on synthetic and natural crystalline arsenic(III) sulfide, As2S3 (orpiment): new data foran old compound. Chemistry of Materials, 18, 3821-3826.CrossRefGoogle Scholar
Gibbs, G.V., Wallace, A.F., Zallen, R., Downs, R.T., Ross, N.L., Cox, D.F. and Rosso, K.M. (2010) Bond paths and van der Waals interactions in orpiment, As2S3 . Journal of Physical Chemistry A, 114, 6550-6557.CrossRefGoogle Scholar
Gibbs, G.V., Wallace, A.F., Downs, R.T., Ross, N.L., Cox, D.F. and Rosso, K.M. (2011) Thioarsenides: a case for long-range Lewis acid-base-directed van der Waals interactions. Physics and Chemistry of Minerals, 38, 267-291.CrossRefGoogle Scholar
Hyršl, J. (2008) The Palomo mine, Huancavelica Department, Peru. Mineralogical Record, 39, 95-99.Google Scholar
Kirkinskii, V.A., Ryaposov, A.P. and Yakushev, V.G. (1967) Phase diagram of arsenic trisulfide at pressures up to 20 kbar. Izvestiya Akademii Nauk SSSR, Neoganicheskie Materialy, 3, 1931-1933.Google Scholar
Mullen, D.J.E. and Nowacki, W. (1972) Refinement of the crystal structures of realgar, AsS and orpiment, As2S3 . Zeitschrift für Kristallographie, 136, 48-65.CrossRefGoogle Scholar
Pascal, P. (1958) Nouveau Traité de Chimie Minérale. Volume 11. Masson, Paris.Google Scholar
Sheldrick, G.M. (2008) SHELXL97 – Program for the refinement of crystal structures. University of Göttigen, Göttigen, Germany.Google Scholar
Srivastava, P., Mund, H.S. and Sharma, Y. (2011) Investigation of electronic properties of crystalline arsenic chalcogenides: theory and experiments. Physica B, 406, 3083-3088.CrossRefGoogle Scholar
Zachariasen, W.H. (1932) The atomic arrangement in glass. Journal of the American Chemical Society, 54, 3841-3851.CrossRefGoogle Scholar
Zallen, R., Slade, M.L. and Ward, A.T. (1971) Lattice vibrations and interlayer interactions in crystalline As2S3 and As2Se3 . Physical Review B, 3, 4257-4273.CrossRefGoogle Scholar
Supplementary material: File

Kampf et al. supplementary material

cif file

Download Kampf et al. supplementary material(File)
File 35.3 KB
Supplementary material: File

Kampf et al. supplementary material

Structure factors

Download Kampf et al. supplementary material(File)
File 74.2 KB