A lodestone, or loadstone, is a naturally magnetized piece of the mineral magnetite. They are naturally-occurring magnets, which can attract iron. The property of magnetism was first discovered in antiquity through lodestones. Pieces of lodestone, suspended so they could turn, were the first magnetic compasses, and their importance to early navigation is indicated by the name lodestone, which in Middle English means 'course stone' or 'leading stone', from the now-obsolete meaning of lode as ‘journey, way’.
Lodestone is one of only two minerals that is found naturally magnetized; the other, pyrrhotite, is only weakly magnetic. Magnetite is black or brownish-black, with a metallic luster, a Mohs hardness of 5.5–6.5 and a black streak.
The process by which lodestone is created has long been an open question in geology. Only a small amount of the magnetite on Earth is found magnetized as lodestone. Ordinary magnetite is attracted to a magnetic field like iron and steel is, but does not tend to become magnetized itself; it has too low a magnetic coercivity (resistance to demagnetization) to stay magnetized for long. Microscopic examination of lodestones has found them to be made of magnetite (Fe3O4) with inclusions of maghemite (cubic Fe2O3), often with impurity metal ions: titanium, aluminium, and manganese. This inhomogeneous crystalline structure gives this variety of magnetite sufficient coercivity to remain magnetized and thus be a permanent magnet.
Lodestone is a Marvel Comics supervillain, who first appears in Darkhawk #7.
A woman named Andrea was hired by crime lord Phillipe Bazin to participate in Project: Lodestone. Phillipe used scientific experiments on Andrea turning her into his superpowered agent called Lodestone. Lodestone was used to fight Phillipe's enemy Darkhawk. After Darkhawk defeated some drug dealers where Headset was injured, Lodestone attacked Darkhawk's alter ego of Chris Powell when he placed his amulet on Headset. After Headset recovered, Chris became Darkhawk and surrendered to prevent any risk of further devastation. Lodestone took Darkhawk back to headquarters where he escaped.
Lodestone continued to serve Phillipe Bazin even at his HQ on Althea Island. Darkhawk arrived there to look for his kidnapped father. During this encounter, Phillipe Bazin was killed and Lodestone was apprehended by the Althean authorities.
Justine Hammer (under her Crimson Cowl alias) recruited Lodestone into her incarnation of the Masters of Evil. Alongside her teammates, she was defeated.
A lodestone is a naturally magnetized piece of the mineral magnetite.
Lodestone may also refer to: