Lead(II) sulfide is a black solid. It does not react with acids. It reacts with air at a high temperature to make lead(II) oxide. It is one of the least toxic forms of lead. This does not mean that it is not toxic, though. It is the result of a test for hydrogen sulfide. Paper soaked in lead(II) acetate is passed through hydrogen sulfide. The colorless lead(II) acetate turns black.
It was once used as a black pigment. Now it is mainly used in infrared detectors.