Zinc sulfide, with addition of a few ppm of a suitable activator, exhibits strong phosphorescence.

The phenomenon was described by Nikola Tesla in 1893,[3] and is currently used in many applications, from cathode-ray tubes through X-ray screens to glow in the dark products.

Zinc sulfide is also used as an infrared optical material, transmitting from visible wavelengths to just over 12 micrometers.

This material when hot isostatically pressed (HIPed) can be converted to a water-clear form known as Cleartran (trademark).

[5] Fine ZnS powder is an efficient photocatalyst, which produces hydrogen gas from water upon illumination.

[6] ZnS was used by Ernest Rutherford and others in the early years of nuclear physics as a scintillation detector, because it emits light upon excitation by x-rays or electron beam, making it useful for X-ray screens and cathode-ray tubes.

[5] As an example, the synthesis of ammonia from methane requires a priori removal of hydrogen sulfide impurities in the natural gas, for which zinc oxide is used.

[8] More conventionally, ZnS is prepared by treating a mildly acidic solution of Zn2+ salts with H2S:[9] This reaction is the basis of a gravimetric analysis for zinc.