A permanent magnet is an object made from a material that is magnetized and creates its own persistent magnetic field. The magnetic field of a permanent magnet is generated by the internal structure of the material itself, specifically the spins and orbits of the electrons and the nucleus of the atoms within the material. Materials that can be magnetized, which are also the ones that are strongly attracted to a magnet, are called ferromagnetic or ferrimagnetic. Ferromagnetic materials can be divided into magnetically "soft" materials like annealed iron, which can be magnetized but do not tend to stay magnetized, and magnetically "hard" materials, which do. Permanent magnets are made from "hard" ferromagnetic materials such as alnico and ferrite that are subjected to special processing in a strong magnetic field during manufacture to align their internal microcrystalline structure, making them very hard to demagnetize. The strongest magnetic field of a permanent magnet is about 8,000 gauss, while the strongest magnets in the world are about 450,000 gauss, which are almost 50 times stronger than that.