Fluorescence: Fluorescence is definitely the home of a mineral to emit obvious light when subjected to ultraviolet radiation. Gypsum won't fluoresce underneath UV mild. Hair or fibre and lime or clay may be extra to plasters through manufacture. The plaster coats, apart from some end coats, are sanded. See also https://www.propanraya.com/id/produk/eco-gypsum-ee-4050