Mineral hydration is an inorganic chemical reaction where water is added to the crystal structure of a mineral, usually creating a new mineral. Rose des Sables (Sand Rose), formed of gypsum crystals In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms in a crystal. ... Minerals are natural compounds formed through geological processes. ...

There are two main ways in which minerals hydrate. One is conversion of an oxide to a double hydroxide, as in the hydration of calcium oxide - CaO - to calcium hydroxide - Ca(OH)₂, the other is incorporation of water molecules directly into the crystalline structure of the mineral, as in the hydration of feldspars to clay minerals. An oxide is a chemical compound of oxygen with other chemical elements. ... Hydroxide is a polyatomic ion consisting of oxygen and hydrogen: OH− It has a charge of −1. ... Calcium oxide (CaO), commonly known as lime, quicklime or burnt lime, is a widely used chemical compound. ... Calcium hydroxide is a chemical compound with the chemical formula Ca(OH)2. ... Feldspar is the name of an important group of rock-forming minerals which make up perhaps as much as 60% of the Earths crust. ... For the town in the United States, see Clay, New York. ...

Some mineral structures, for example, montmorillonite, are capable of including a variable amount of water without significant change to the mineral structure. Montmorillonite is a very soft phyllosilicate mineral that typically forms in microscopic crystals, forming a clay. ...

Hydration is the mechanism by which Portland cement develops strength. Sampling fast set Portland cement Portland cement is the most common type of cement in general usage, as it is a basic ingredient of concrete, mortar and plaster. ...