1Melinda J. Rucks, 1,2Matthew L. Whitaker, 1Timothy D. Glotch,1,2 John B. Parise, 1Steven J. Jaret, 1Tristan Catalano, 3M. Darby Dyar
American Mineralogist 103, 1516-1519 Link to Article [https://doi.org/10.2138/am-2018-6539]
1Department of Geosciences, Stony Brook University, Stony Brook, New York 11794-2100, U.S.A.
2Mineral Physics Institute, Stony Brook University, Stony Brook, New York 11794-2100, U.S.A
3Department of Astronomy, Mount Holyoke College, South Hadley, Massachusetts 01075, U.S.A.
Copyright: The Mineralogical Society of America
Tissintite is a shock-induced, Ca-rich mineral, isostructural to jadeite, observed in several meteorite samples such as the martian shergottite Tissint. It may form within a “Goldilocks Zone,” indicating a potential to provide strict constraints on peak pressure and temperature conditions experienced during impact. Here we present the first laboratory synthesis of tissintite, which was synthesized using a large volume multi-anvil apparatus at conditions ranging from 6–8.5 GPa and 1000–1350 °C. For these experiments, we utilized a novel heating protocol in which we reached impact-relevant temperatures within 1 s and in doing so approximated the temperature-time conditions in a post-shock melt. We have established that heating for impact-relevant timescales is not sufficient to completely transform crystalline labradorite to tissintite at these pressures. Our findings suggest that tissintite forms from amorphous plagioclase during decompression.