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Magnetite has been important in understanding the conditions under which rocks form. Magnetite reacts with oxygen to produce hematite, and the mineral pair forms a buffer that can control how oxidizing its environment is (the oxygen fugacity). This buffer is known as the hematite-magnetite or HM buffer.
Iron(II,III) oxide, or black iron oxide, is the chemical compound with formula Fe 3 O 4.It occurs in nature as the mineral magnetite.It is one of a number of iron oxides, the others being iron(II) oxide (FeO), which is rare, and iron(III) oxide (Fe 2 O 3) which also occurs naturally as the mineral hematite.
Iron(III) oxide was the most common magnetic particle used in all types of magnetic storage and recording media, including magnetic disks (for data storage) and magnetic tape (used in audio and video recording as well as data storage). Its use in computer disks was superseded by cobalt alloy, enabling thinner magnetic films with higher storage ...
A magnet's magnetic moment (also called magnetic dipole moment and usually denoted μ) is a vector that characterizes the magnet's overall magnetic properties. For a bar magnet, the direction of the magnetic moment points from the magnet's south pole to its north pole, [ 15 ] and the magnitude relates to how strong and how far apart these poles ...
Magnetism is the class of physical attributes that occur through a magnetic field, which allows objects to attract or repel each other.Because both electric currents and magnetic moments of elementary particles give rise to a magnetic field, magnetism is one of two aspects of electromagnetism.
Magnetic mineralogy is the study of the magnetic properties of minerals. The contribution of a mineral to the total magnetism of a rock depends strongly on the type of magnetic order or disorder. Magnetically disordered minerals (diamagnets and paramagnets) contribute a weak magnetism and have no remanence.
The Verwey transition is a low-temperature phase transition in the mineral magnetite associated with changes in its magnetic, electrical, and thermal properties. [1] It typically occurs near a temperature of 120 K but is observed at a range of temperatures between 80 and 125 K, although the spread is generally tight around 118-120 K in natural magnetites.
One of the earliest known references to lodestone's magnetic properties was made by 6th century BC Greek philosopher Thales of Miletus, [12] whom the ancient Greeks credited with discovering lodestone's attraction to iron and other lodestones. [13] The name magnet may come from lodestones found in Magnesia, Anatolia. [14]