Fluorescence: Fluorescence Is the home of a mineral to emit noticeable light-weight when subjected to ultraviolet radiation. Gypsum would not fluoresce underneath UV light. Hair or fibre and lime or clay might be added to plasters during manufacture. The plaster coats, apart from some end coats, are sanded. See also https://www.propanraya.com/id/produk/eco-gypsum-ee-4050