Thomson, Andrew;
Crichton, Wilson;
Siersch, Nicki;
Ezad, Isra;
Dobson, David;
Brodholt, John;
(2025)
Experimental observations of CaSiO₃-CaTiO₃ perovskites: implications for Ca-rich inclusions observed in sub-lithospheric diamonds.
Physics and Chemistry of Minerals
, 52
, Article 19. 10.1007/s00269-025-01321-z.
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Abstract
Calcium perovskite is a major component of deep mantle phase assemblages and has been frequently identified, in retrograde form, as polyphase mineral inclusions within sub-lithospheric diamonds. Here experimental observations of synthetic samples demonstrate various properties of calcium perovskite minerals which have relevance for the interpretation of diamond-hosted inclusions. Ambient pressure diffraction and spectroscopy confirm the linear dependence of crystallographic unit cell volume and Raman peak shifts across the entire CaSiO3-CaTiO3 binary join. These systematics will allow verification of perovskite structure and constraint of inclusion composition, without destructive analyses, in future studies. Additionally, high pressure observations confirm that calcium perovskite minerals ≳ 80 mol.% CaSiO3 undergo spontaneous amorphization during decompression at room temperature, meaning they are unrecoverable. Finally, the presence of water appears to expand the calcium perovskite stability field to lower pressure conditions, implying at least some appreciable water-solubility in these minerals.
| Type: | Article |
|---|---|
| Title: | Experimental observations of CaSiO₃-CaTiO₃ perovskites: implications for Ca-rich inclusions observed in sub-lithospheric diamonds |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1007/s00269-025-01321-z |
| Publisher version: | https://doi.org/10.1007/s00269-025-01321-z |
| Language: | English |
| Additional information: | This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. |
| Keywords: | Calcium silicate perovskite, X-ray diffraction, Raman spectroscopy, Sublithospheric diamonds, Mantle mineralogy |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Earth Sciences |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10207503 |
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