Barium Orthothioantimonate, Ba₃Sb₂S₈.6H₂O

Barium Orthothioantimonate, Ba₃Sb₂S₈.6H₂O, is formed, as bright yellow crystals soluble in water, by the action of barium hydrosulphide on antimony pentasulphide. By adding a large excess of potassium chloride to the solution the compound KBaSbS₄.6H₂O, or K₃SbS₄. Ba₃(SbS₄)₂.18H₂O, is obtained as colourless crystals which darken on exposure to air. When heated they melt and lose water.