Gypsum and anhydrite from the Neogene of the central Jordan valley associated with basalt bodies in the Menahamiya area contain abundant euhedral magnetite and diopside crystals and rarer grossular. The original calcareous shales above the gypsum were transformed into hydrogrossular cemented by secondary calcite and gypsum. The mineralization is assumed to be due to low-temperature, high water-pressure metasomatic activity similar to the process of rodingization. The described occurrence is unusual in that the hydrothermal solutions may have been partly formed in situ by thermal dehydration of the gypsum. In a nearby locality, Tel Shaharit, the mineralization occurred in a calcareous environment producing thomsonite, natrolite, and hydrogrossular.