Dervillite, Ag2AsS2, from Lengenbach quarry, Binn valley, Switzerland: occurrence and crystal structure | Mineralogical Magazine | Cambridge Core (original) (raw)

Abstract

Dervillite, As2AsS2, has been found in a sample from the Lengenbach quarry in the Binn Valley, Valais, Switzerland. It occurs as very rare crystals up to 200 μm across on jordanite. Dervillite is opaque with a metallic lustre and shows a dark brown streak. The structure is monoclinic, space group Pc, with a = 9.6155(7), b = 12.9331(8), c = 6.8616(5) A ˚ , b = 99.352(8)º, V = 842.0(1) Å3 and Z = 8. In the crystal structure [R1 = 0.060 for 2370 reflections with I > 2σ(I)], silver adopts various coordinations extending from quasi linear to quasi tetrahedral whereas arsenic forms very peculiar crystal-chemical environments, such as As(S2As) and As(S2AsAg). Such metalloid–metalloid or metal–metalloid bonds account for the apparent charge imbalance observed in the chemical formula.

References

Bari, H., Cesbron, F., Moelo, Y., Permingeat, F., Picot, P., Pierrot, R., Schubnel, H.J. and Weil, R. (1983) La dervillite, Ag2AsS2, nouvelle définition de l’espèce. Bullettin de Minéralogie, 106, 519–524.CrossRefGoogle Scholar

Bindi, L., Evain, M. and Menchetti, S. (2006) Temperature dependence of the silver distribution in the crystal structure of natural pearceite, (Ag,Cu)16(As,Sb)2S11. Acta Crystallographica, B62, 212–219.CrossRefGoogle Scholar

Bindi, L., Evain, M. and Menchetti, S. (2007) Complex twinning, polytypism and disorder phenomena in the crystal structures of antimonpearceite and arsenpolybasite. The Canadian Mineralogist, 45, 321–333.CrossRefGoogle Scholar

Bindi, L., Catelani, T., Chelazzi, L. and Bonazzi, P. (2008) Reinvestigation of the crystal structure of lautite, CuAsS. Acta Crystallographica, E64, i22.Google Scholar

Bindi, L., Downs, R.T. and Menchetti, S. (2010a) The crystal structure of billingsleyite, Ag7(As,Sb)S6, a sulfosalt containing As5+ . The Canadian Mineralogist, 48, 155–162.CrossRefGoogle Scholar

Bindi, L., Nestola, F., Guastoni, A. and Secco, L. (2010b) The crystal structure of dalnegroite, Tl5–xPb2x (As,Sb)21–xS34: A masterpiece of structural complexity. Mineralogical Magazine, 74, 999–1012.CrossRefGoogle Scholar

Bindi, L., Nestola, F., Guastoni, A., Peruzzo, L., Ecker, M. and Carampin, R. (2012a) Raberite, Tl5Ag4As6SbS15, a new Tl-bearing sulfosalt from Lengenbach quarry, Binn Valley, Switzerland: description and crystal structure. Mineralogical Magazine, 76, 1153–1163.CrossRefGoogle Scholar

Bindi, L., Nestola, F., Guastoni, A., Zorzi, F., Peruzzo, L. and Raber, T. (2012b) Te-rich canfieldite, Ag8Sn(S,Te)6, from Lengenbach quarry, Binntal, Canton Valais, Switzerland: Occurrence, description and crystal structure. The Canadian Mineralogist, 50, 111–118.CrossRefGoogle Scholar

Bindi, L., Spry, P.G., Bonazzi, P., Makovicky, E. and Balić-Žunić, T. (2013) Quadratite, AgCdAsS3: Chemical composition, crystal structure and OD character. American Mineralogist, 98, 242–247.CrossRefGoogle Scholar

Bonazzi, P. and Bindi, L. (2008) A crystallographic review of arsenic sulfides: Effects of chemical variations and changes induced by light exposure. Zeitschrift für Kristallographie, 223, 132–147.Google Scholar

Bonazzi, P., Borrini, D., Mazzi, F. and Olmi F. (1995) Crystal structure and twinning of Sb2AsS2, the synthetic analogue of pääkkonenite. American Mineralogist, 80, 1054–1058.CrossRefGoogle Scholar

Downs, R.T., Bartelmehs, K.L., Gibbs, G.V. and Boisen, M.B., Jr. (1993) Interactive software for calculating and displaying X-ray or neutron powder diffractometer patterns of crystalline materials. American Mineralogist, 78, 1104–1107.Google Scholar

Engel, P. and Nowacki, W. (1966) Die Verfeinerung der Kristallstruktur von Proustit, Ag3AsS3, und Pyrargyrit, Ag3SbS3. Neues Jahrbuch für Mineralogie Monatshefte, 1966, 181–195.Google Scholar

Flack, H.D., Bernardinelli, G., Clemente, D.A., Lindenc, A. and Spek, A.L. (2006) Centrosymmetric and pseudo-centrosymmetric structures refined as noncentrosymmetric. Acta Crystallographica, B62, 695–701.CrossRefGoogle Scholar

Graeser, S., Cannon, R., Drechsler, E., Raber, T. and Roth, P. (2008) Faszination Lengenbach Abbau- Forschung-Mineralien 1958–2008. Kristallographik Verlag, Achberg, Germany.Google Scholar

Guastoni, A., Bindi, L. and Nestola, F. (2012) Debattistiite, Ag9Hg0.5As6S12Te2, a new Te-bearing sulphosalt from Lengenbach quarry, Binn valley, Switzerland: Description and crystal structure. Mineralogical Magazine, 76, 743–750.CrossRefGoogle Scholar

Ibers, J.A. and Hamilton, W.C. Eds. (1974) International Tables for X-ray Crystallography, vol. IV, 366 p. Kynock, Dordrecht, The Netherlands.Google Scholar

Makovicky, E., Johan, Z. and Karup-Møller, S. (1980) New data on bukovite, thalcusite, chalcothallite and rohaite. Neues Jahrbuch für Mineralogie Abhandlungen, 138, 122–146.Google Scholar

Müller, P., Herbst-Irmer, R., Spek, A.L., Schneider, T.R. and Sawaya, M.R. (2006) Crystal Structure Refinement, a Crystallographer’s Guide to SHELXL. Oxford University Press (for IUCr), London, 213 pp.CrossRefGoogle Scholar

Nestola, F., Guastoni, A., Bindi, L. and Secco L. (2010) Dalnegroite, Tl5-xPb2x(As,Sb)21-xS34, a new thallium sulphosalt from Lengenbach quarry, Binntal, Canton Valais, Switzerland. Mineralogical Magazine, 73, 1027–1032.CrossRefGoogle Scholar

Ribár, B. and Nowacki, W. (1970) Die Kristallstruktur von Stephanit, [Sb S 3 | S | A g 5 I I I ]. A ct a Crystallographica, B26, 201–207.Google Scholar

Shannon, R.D. (1976) Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Acta Crystallographica, A32, 751–767.CrossRefGoogle Scholar

Weil, R. (1941) La dervillite, espèce minérale nouvelle. Revue des Sciences Naturelles d’Auvergne, Clermont Ferrand, 7, 110–111.Google Scholar

Yang, H., Downs, R.T., Costin, G. and Eichler, C.M. (2007) Crystal structure and revision of chemical formula of tvalchrelidzeite, Hg3SbAsS3. The Canadian Mineralogist, 45, 1529–1533.CrossRefGoogle Scholar