Ca sulfate in Jbilet Winselwan. (A) Backscattered electron image of a calcite (CC) grain surrounded by Ca sulfate (AH). This is a typical occurrence of Ca sulfate throughout the matrix of this meteorite, suggesting that the anhydrite precipitation by hydrothermal alteration at >300°C took place subsequently after the calcite precipitation by low-temperature (0°C–70°C) aqueous alteration. (B) Raman spectrum of the Ca sulfate. The peaks of the Raman shift observed for Jbilet Winselwan are consistent with those of anhydrite showing the characteristic Raman bands at 1017 and 1129 cm−1 (Prieto-Taboada et al. 2014).