Magnesia may refer to:

Chemistry and geology

Magnesium oxide Magnesium oxide (MgO), or magnesia, is a white hygroscopic solid mineral that occurs naturally as periclase and is a source of magnesium (see also oxide). It has an empirical formula of MgO and consists of a lattice of Mg2+ ions and O2− ions ...

Periclase Periclase is a magnesium mineral that occurs naturally in contact metamorphic rocks and is a major component of most basic refractory bricks. It is a cubic form of magnesium oxide ( Mg O). In nature it usually forms a solid solution with wüstit ...

or magnesia, a natural mineral of magnesium oxide *

Magnesian limestone (disambiguation) The Magnesian Limestone is a suite of carbonate rocks in north-east England dating from the Permian period. The outcrop stretches from Nottingham northwards through Yorkshire and into County Durham where it is exposed along the coast between Ha ...

Magnesium Magnesium is a chemical element; it has Symbol (chemistry), symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 ...

Milk of magnesia Magnesium hydroxide is an inorganic compound with the chemical formula Mg(OH)2. It occurs in nature as the mineral brucite. It is a white solid with low solubility in water (). Magnesium hydroxide is a common component of antacids, such as milk o ...

, a suspension of magnesium hydroxide

Geography

Magnesia (hypothetical city) Magnesia may refer to: Chemistry and geology *Magnesium oxide **Periclase or magnesia, a natural mineral of magnesium oxide *Magnesian limestone (disambiguation) *Magnesium *Milk of magnesia, a suspension of magnesium hydroxide Geography * Magn ...

, a future colony of Knossos, imagined in Plato's ''

Laws Law is a set of rules that are created and are law enforcement, enforceable by social or governmental institutions to regulate behavior, with its precise definition a matter of longstanding debate. It has been variously described as a Socia ...

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Magnesia (regional unit) Magnesia (, ''Magnisía'', , Ancient Greek: ''Magnēsía'', deriving from the tribe name ''Magnetes'') is one of the regional units of Greece. It is part of the modern regions of Greece, region of Thessaly. Its capital is the city of Volos. About ...

, the southeastern area of Thessaly in central Greece *

Ancient Magnesia Anciently, Magnesia () was a region of Ancient Greece, eventually absorbed by ancient Thessaly. Originally inhabited by the Magnetes (Μάγνητες), Magnesia was the long and narrow slip of country between Mounts Mount Ossa (Greece), Ossa and ...

, a historical region of Greece with borders differing from the modern regional unit *

Magnesia ad Sipylum Magnesia Sipylum ( or ; modern Manisa, Turkey) was a city of Lydia, situated about 65 km northeast of Smyrna (now İzmir) on the river Hermus (now Gediz) at the foot of Mount Sipylus. The city should not be confused with its older neigh ...

, a city of Lydia, now Manisa in Turkey **

Battle of Magnesia The Battle of Magnesia took place in either December 190 or January 189 BC. It was fought as part of the Roman–Seleucid War, pitting forces of the Roman Republic led by the Roman consul, consul Lucius Cornelius Scipio Asiaticus and the allied ...

, 190 BC, the concluding battle of the Roman–Seleucid War *

Magnesia on the Maeander Magnesia may refer to: Chemistry and geology *Magnesium oxide ** Periclase or magnesia, a natural mineral of magnesium oxide * Magnesian limestone (disambiguation) *Magnesium * Milk of magnesia, a suspension of magnesium hydroxide Geography * M ...

, an ancient Greek city in Anatolia *

Magnesia Prefecture Magnesia Prefecture () was one of the prefectures of Greece. Its capital was Volos. It was established in 1899 from the Larissa Prefecture. The prefecture was disbanded on 1 January 2011 by the Kallikratis programme, and split into the regional ...

, a former prefecture of Greece {{disambiguation, geo