What is Gypsum?
Calcium Sulphate Dihydrate (CaSO4.2H2O) deposited in sedimentary layers on the sea bed some 100-200 million years back when the seas evaporated.
Under high pressure and temperature Gypsum turns into Anhydrite (CaSO4).
Gypsum is formed by the hydration of Anhydrite. In nature, Gypsum and Anyhdrite occur as beds or nodular masses up to a few meters thick. The depth of hydration can range from the surface of the deposit down to three hundred meters, depending on temperature and pressure, topography and the structure of the deposit.
The content of Gypsum in sedimentary rock varies from 75% to 95%, the rest being clay and chalk.

Geological History of Gypsum in Saudi Arabia

• The deposits in the west (Arabian Gulf) and the east (Red Sea) formed during Cenozoic era, in the tertiary and Quaternary periods, whereas in the central parts of the country are from Mesozoic era and formed in the Jurassic and Triassic periods, some 200 – 250 million years ago.
• El Khayyat Gypsum Factories has an advantage because our quarries are located in the western part of the kingdom and gypsum are formed in Cenozoic era wherein gypsum are intact and with the heighest purity compared to the other parts. Cenozoic era is considered as the current and the most recent of the three classic geological eras 65.5 million years ago..
  Its application ranges from gypsum plaserboard (drylining) via wall plaster (wet plastering), partition panels, gypsum, stucco and decorative panels, floating screed, to special plasters and gypsum leveling compounds.