Aluminum oxide, often called alpha-alumina or alumina, is an alkaline earth compound that contains aluminum and oxygen atoms. Oxygen atoms gain three electrons, while aluminum atoms lose three electrons during the oxidation process. The chemical substance is white and odorless and can be produced through a variety of methods.
Aluminium oxide is found in nature as corundum, rubies, and sapphires. It is also an important industrial chemical.
It is used in a wide range of manufacturing applications, from refractories and ceramics to abrasives. It is a good ceramic material with many useful properties such as high thermal conductivity, dielectric strength, and resistance to air and water vapor.
The boiling point of aluminium oxide is 660 degrees Celsius or 1220 Fahrenheit, and the melting point is higher. It is also very corrosion resistant, making it an ideal choice for a number of applications.
Alumina is an excellent metal for adsorbents and catalysts, because it has a high specific surface area, which allows more effective adsorption of chemicals. It is also a very versatile material that can be manufactured into hard, wear-resistant materials for a range of applications.
In nature, it is a common mineral in igneous and metamorphic rocks. The most common crystalline form is corundum, which forms a trigonal Bravais lattice with a space group of R-3c (number 167 in the International Tables). A hexagonally closest packed oxygen ion occupies two-thirds of the octahedral interstices.
It is an essential ingredient in the fabrication of metallic aluminium, and is responsible for the corrosion resistance of this metal. This corrosion resistance is a result of the formation of a thin passivation layer on the metal which protects it from further weathering. This layer can be strengthened by a process called anodising, which involves a discharge-assisted oxidation of the metal.