Abstract

The crystal structure and chemical composition of two crystals (labelled ET1 and ET2) of strontian soda melilite from Mt. Etinde, Cameroon, are investigated. Quantitative analysis leads to the following formulae: (Ca 0.84 Sr 0.45 Na 0.71 )(Mg 0.19 Fe 2+ 0.06 Mn 0.03 Zn 0.02 Al 0.46 Fe 3+ 0.23 Ti 0.01 )(Si 1.99 Al 0.01 )O 7.00 and (Ca 0.83 Sr 0.45 Na 0.72 ) (Mg 0.20 Fe 2+ 0.06 Mn 0.01 Zn 0.01 Al 0.45 Fe 3+ 0.24 Ti 0.02 )(Si 1.99 Al 0.01 )O 7.00 , for ETl and ET2 respectively. Lattice parameters are: a = 7.754(1), c = 5.101(1) A for ET1 and a = 7.764(1), c = 5.095(1) A for ET2. The structure is refined up to R all = 2.64 and 2.78 %, respectively, using 430 independent reflections. Substitution of Sr for Ca causes sufficient modification of the tetrahedral layer to destabilize the incommensurate modulated structure.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.