Seawater barium and sulfide removal improved marine habitability for the Cambrian Explosion of early animals. Science China Press. Journal National Science Review DOI 10.1093/nsr/nwae237.

Example: Sodium sulphide when mixed with barium chloride, a precipitate of barium sulphide forms along with sodium chloride as a solution. Na₂S + BaCl₂ → BaSO₄↓ + 2NaCl.