The active compound in mineral gypsum and phosphogysum is

The active compound in mineral gypsum and phosphogypsum is Calcium sulphate.
Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO₄·2H₂O.
Phosphogypsum (PG) is the calcium sulfate hydrate formed as a by-product of the production of fertilizer from phosphate rock. It is mainly composed of gypsum.
Although gypsum is a widely used material in the construction industry, phosphogypsum is usually not used but is stored indefinitely because of its weak radioactivity.