From thorite to coffinite: A spectroscopic study of Th1−xUxSiO4 solid solutions

- Synthetic uranothorites, thorite, and coffinite were characterized by Raman and FTIR.
- Formulation of synthetic uranothorites was unambiguously set as Th1−xUxSiO4.
- No trace of water, hydroxyl groups or uranyl entities were detected.
- ν1 and ν2 vibrations of SiO4 were shown to present a linear shift versus composition.
- Critical review of the values and assignments reported for coffinite was provided.