Magma (from Greek μάγμα “mixture”) is a complex high-temperature fluid substance made of molten or semi-molten rock, volatiles and solids. It may also contain suspended crystals and dissolved gas.

Magma develops within the mantle or crust when the temperature-pressure conditions favor the molten state and rises toward the Earth’s surface when a structural zone allows movement.

It can remain in a chamber until it cools and crystallizes forming igneous rock, it erupts as a volcano, or moves into another magma chamber.

The Latin word machina derives from the Greek (Doric μαχανά makhana, Ionic μηχανή mekhane “contrivance, machine, engine”, a derivation from μῆχος mekhos “means, expedient, remedy”).