Preparation of barium sulfide | Ba(NO3)2 + H2S = BaS + 2HNO3
Of all the alkaline earth elements, only barium forms a sulfide stable enough to fall out of the aqueous solution (by the way, in the form of a crystalline hydrate).
In industry, it is obtained by reducing barium sulfate. Barium sulfide has the properties of a semiconductor, but in electronics is very limited.
Ba(NO3)2 + H2S = BaS + 2HNO3