| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1409045 | Journal of Molecular Structure | 2012 | 8 Pages |
Raman spectroscopy complimented with infrared spectroscopy has been used to study the variation in molecular structure of two minerals of the apophyllite mineral group, namely apophyllite-(KF) KCa4Si8O20F·8H2O and apophyllite-(KOH) KCa4Si8O20(F,OH)·8H2O. apophyllite-(KF) and apophyllite-(KOH) are different minerals only because of the difference in the percentage of fluorine to hydroxyl ions. The Raman spectra are dominated by a very intense sharp peak at 1059 cm−1. A band at around 846 cm−1 is assigned to the water librational mode. It is proposed that the difference between apophyllite-(KF) and apophyllite-(KOH) is the observation of two Raman bands in the OH stretching region at around 3563 and 3625 cm−1. Multiple water stretching and bending modes are observed showing that there is much variation in hydrogen bonding between water and the silicate surfaces.
► We have studied minerals of the apophyllite group. ► Fluorapophyllite and hydroxyapophyllite are distinguished by their Raman spectrum in the OH stretching region. ► The materials are zeolitic in nature.
