Article contents
On the infra-red spectrum and thermal decomposition products of thaumasite1, Ca3H2(CO3/SO4)SiO4.13H2O
Published online by Cambridge University Press: 14 March 2018
Summary
The infra-red spectrum of untreated thaumasite Ca3H2(CO3/SO4)SiO4.13H2O, as well as the spectra and X-ray diffraction patterns of thaumasite heated in air at 200, 360, 550, 725, 800, 900, and 1150° C were investigated. The release of CO2 and H2O upon heating was followed. It was established that thaumasite changes between 200 and 550° C to a glass-like, amorphous state. Ca2SiO4-polymorphs and anhydrite are formed upon heating at temperatures up to 800° C. From 900° C calcium silicosulphate and anhydrite are the thermal decomposition products. These results are used in the assignment of the IR-absorption bands under 1400 cm−1 of untreated thaumasite, which are shown to be of a composite nature, i.e. attributable to overlapping vibrations of both sulphate and silicate tetrahedra.
- Type
- Research Article
- Information
- Mineralogical magazine and journal of the Mineralogical Society , Volume 36 , Issue 283 , September 1968 , pp. 1003 - 1011
- Copyright
- Copyright © The Mineralogical Society of Great Britain and Ireland 1968
Footnotes
Present address: Institute of Physical Chemistry, Bulgarian Academy of Sciences, Sofia 13, Bulgaria.
This paper was presented in part at the Seventh I.U.Cr. Congress in Moscow, July 1966.
References
- 9
- Cited by