The structural formula of a hydrous amphibole
- 1 September 1955
- journal article
- Published by Mineralogical Society in Mineralogical Magazine and Journal of the Mineralogical Society
- Vol. 30 (230) , 717-722
- https://doi.org/10.1180/minmag.1955.030.230.05
Abstract
The majority of amphiboles conform to the general structural formula X2-3Y5Z8O22(OH,F,Cl)2, where X = Na, K, Ca, Y - Mg, Fe″, Mn, A1, Fe‴, Ti, and Z = Si, A1 or Ti. Two X ions occupy the positions filled by Ca in the ideal tremolite structure; the additional X ions are assumed to occur in the 'A' sites which are vacant in tremolite.For the amphiboles, therefore, the method most commonly adopted for deriving a formula from a chemical analysis is to assume that a total of 24 anions is present in the formula unit.Keywords
This publication has 3 references indexed in Scilit:
- A further note On the presentation of chemical analyses of mineralsMineralogical Magazine and Journal of the Mineralogical Society, 1954
- The Crystal Chemistry of Montmorillonite—II. Calculation of the Structural FormulaClay Minerals, 1951
- On the presentation of chemical analyses of mineralsMineralogical Magazine and Journal of the Mineralogical Society, 1939