5 gypsum types in terms of appearance and texture
Gypsum is a non-metallic mineral that exists in nature as solid forms with the chemical formula CaSO4. 2H2O. The English term gypsum is used for this solid massive form, while the baked gypsum is called plaster. Gypsum is a natural calcium sulfate hydrate in several crystalline forms found in the Earth’s solid crust deposits. It is divided into five gypsum types in terms of construction and texture:
1- Alabaster
A massive fine-grained type of gypsum, called alabaster, was derived from the name of a place in ancient Egypt called Alabaston where the mineral was used for sculpture and statuary.
2- Selenite
The crystalline and transparent form, the name selenite, was derived from the Greek word selene, meaning the moon.
3- Satin Spar
The fibrous type with a silk-like sheen, named satin spar, was derived from a type of silk fabric called satin.
4- Gypset (gypsum clay)
A type of impure gray porous gypsum, mixed with sand and clay, which is formed as large and thick sediments.
5- Gypsum
Medium- to coarse-grained gypsum that sediments as large and thick layers.
Economic importance of gypsum types
Gypsum and alabaster are very important types from the economic and mining point of view. In general, there is often no difference between the two types, and both are called gypsum, as they are the same in terms of chemical composition and properties.
