The Stabilities of Secondary Tin Minerals: Abhurite and its Relationships to Sn(II) and Sn(IV) Oxides and Oxyhydroxides

R. Edwards, R. D. Gillard and P. A. Williams^*

School of Chemistry and Applied Chemistry, University of Wales College of Cardiff, P.O. Box 912, Cardiff CF1 3TB, U.K.

^*Present address: Department of Chemistry, University of Western Sydney Nepean, P.O. Box 10, Kingswood, NSW 2747, Australia.

Abstract: The true formula of abhurite is Sn₂₁Cl₁₆(OH)₁₄O₆. A stability constant for the phase has been determined at 298.2 K. For the reaction Sn₂₁Cl₁₆(OH)₁₄O₆ (s) + 26H⁺ (aq) ⇌ 21Sn²⁺ (aq) + 16Cl⁻ (aq) + 20H₂O (1), log K_H+ (298.2 K) is equal to −39.9 (7). This value is used to assess the relative stability of abhurite in the natural environment and to evaluate its modes of occurrence in relation to other secondary Sn(II) and Sn(IV) species.

Keywords: abhurite • tin minerals • stability constant

Mineralogical Magazine; June 1992 v. 56; no. 383; p. 221-226; DOI: 10.1180/minmag.1992.056.383.08
© 1992, The Mineralogical Society
Mineralogical Society (www.minersoc.org)