Dysprosium(III) sulfide is a binary inorganic compound of dysprosium and sulfur with the chemical formula Dy2S3.

[1][2][3][4] Heating of pure substances in an inert atmosphere or vacuum: The effect of hydrogen sulfide on dysprosium(III) oxide: Didysprosium trisulfide forms yellow-orange-brown crystals of two modifications: cubic and monoclinic systems.

[5] There is evidence that Dy2S3 forms crystals of brown-red, black, or green color.

The compound is moderately soluble in water and acids.

[6] Dy2S3 oxidizes when strongly heated in air: