As its name suggests, natural gypsum is mineral found in nature. Large Gypsum Deposits occur in many countries. They have form by crystallization of Saturated aqueous solutions in shallow marine areas. During this process, inversely to their solubility sequence, first the carbonates, then sulfates and finally chlorides deposited. This lead to the formation of gypsum deposits with thickness of a few meters up to, in exceptional cases, 400 meters. This deposits first consisted of gypsum. As a result of other storing sedimentation on the top of the gypsum and the corresponding rise in temperature, the gypsum (CaSO4 2H2O) was converted to anhydrite (CsSO4) so that the calcium sulfate deposits from the geological past consisted almost entirely of anhydrite.
Because of the geological history, gypsum rocks differs in terms of purity, color and rock fabric. On the MOH’s scale of mineral hardness, gypsum has hardness of 1.5 – 2.0. The density of gypsum rock is 2.2 – 2.4 kg/m2. Natural impurities are sediments which settled out together with the gypsum in the marine basins, such as Limestone, Marl, Clay and sometimes Sands, Bitumen or various saltes. Some of these natural impurities impart specific benefecial building physical properties to the products made from these materials, such as gypsum plasterboard.
History of Gypsum Use
Gypsum has a lone story as a versatile material. It is one of the oldest building materials ever used by human beings. The ancient egyptians already used it for the pyramid of cheops (Khufu) and the pyramid of Chefren (Khafre). And yet gypsum is proven to have been used as a binder even 4,500 years earlier in the construction of the towers of jericho. The oldest secure evidence of the use of gypsum was found in the town of Catal Huyuk in asia minor. These finds date back to around 9000 before the common era..
The word gypsum is derived from ancient Greek, the Greeks called this material “Gypsos”, a “Gypsum” in english, for instance, the German language makes no distinction between the gypsum rock and the binder, using “GIPS” for both. This is different in other languages, such as in English where “Gypsum” denotes the raw mineral and “Plaster” signifies gypsum as a binding agent.
Years ago Saudi Arabia had been exporting gypsum products from Nearby countries but after it was discovered that the place has a vast gypsum deposit, bussinessmen were starting to build gypsum factories and now becoming the leading supplier of quality gypsum products in the region and even started spreading throughout the world, evidently natural gypsum in the kingdom is considered as the best compared to other countries because of its quality, color, purity, strength and other aspect especially those found in the western part where the El Khayyat Quarries are located.
Ancient History
The Ancient egyptians used gypsum plaster 5,000 years ago to mortar the stones of the Cheops Pyramid. The sandy environment along the Nile is an ideal place for gypsum to form as the river’s annual flooding deposits calcium sulfate, which remains once the flooding is over. The Egyptians gathered the gypsum crystals, burned them to dehydrate them and then crushed them into powder. this process for making the plaster has changed little since that time.