An oxide is a chemical compound of oxygen with other chemical elements, rust (iron oxide) or bauxite (aluminium oxide), usually created through the process of oxidation. Oxides are extremely common in Earth's crust, and indeed in solid matter throughout the universe. Oxides can be named by how many oxygen atoms are in the molecule, dioxide for 2, trioxide for 3, tetroxide for 4, pentoxide for 5, hexoxide for 6, and heptoxide for 7.
Generally, oxides are not conductive to electricity. This property is most commonly taken advantage of with silicon dioxide, as silicon can easily be oxidized and the resulting part can be made into a transistor. This is the basis for much of modern computer technology.
In the 18th century, oxides were named calx after the calcination process used to produce oxides. Calx was later replaced by oxyd.
Oxide can also refer to the Oxide Design Co., a U.S. strategic design firm.