a soft sulfate mineral composed of calcium sulfate dihydrate. The mineral goes through a process of cooking, at variable temperature, where it is dehydrated and pulverized. Gypsum is also known as “scagliola”, that is the most selected and highest gyspsum quality. Upon addition of water, after a few tens of minutes the dehydrated gypsum becomes regular gypsum (dihydrate) again, causing the material to harden or "set" in ways that are useful for casting and construction (that is, it becomes “plaster gypsum”). In the construction industry, gypsum is used in plasters or pre-mixed products in order to produce moulds, frames, statues. Gypsum is normally used for internal renovations and, if properly treated, it may be used for external renovations as well. It is fire resistant.
