A Tutton's salt may be heat treated and dehydrate, e.g. (NH4)2Mn2(SeO4)3 can be made from (NH4)2Mn(SeO4)3·6(H2O) heated to 100 °C, forming (NH4)2(SeO4) as a side product. Similarly the ammonium vandadium Tutton's salt, (NH4)2V(SO4)2, heated to 160 °C in a closed tube produces (NH4)2V2(SO4)3. At lower temperatures a hydroxy compound is formed. Few uses have been made of these substances. Lanbeinite itself can be used as an "organic" fertiliser with potassium, magnesium and sulfur, all needed for plant growth. Electrooptic devices could be made from some of these crystals, particularly those that have cubic transition temperatures as temperatures above room temperature. Research continues into this. Ferroelectric crystals could store information in the location of domain walls. The phosphate langbeinites are insoluble, stable against heat, and can accommodate a large number of different ions, and have been considered for immobilizing unwanted radioactive waste. Rare earth containing zirconium phosphate langbeinites have been investigated for use in white LEDs and plasma displays. Langbeinites that contain bismuth are photoluminescent. In case of iron-containing ones complex magnetic behavior may be found.