Zinc sulfide is a white powder of composition ZnS.H²O. It is used as a paint pigment, for whitening rubber and for paper coating. The zinc sulfide phosphors which produce luminescence by exposure to light are made with zinc sulfide mixed with about 2% sodium chloride (NaCl) and 0,005% copper, manganese or other activator, and fired in a nonoxidizing atmosphere. The cubic Crystal structure of zinc sulfide changes to a stable hexagonal structure at 1020°C, but both have the phosphor properties.
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