The question of whether gold and silver are magnetic is common for anyone handling precious metals or curious about basic physics. Magnetism describes how a material responds to an external magnetic field, resulting in attraction, weak attraction, or repulsion. Only a few metals, such as iron, nickel, and cobalt, exhibit the strong attraction most people associate with magnetism. Gold and silver do not belong to this group and are classified as non-magnetic in the common sense of the word.
The Simple Answer: Interaction with Standard Magnets
For practical purposes, pure gold and pure silver are not magnetic. If a common magnet is held next to a pure gold coin or a silver bullion bar, no attraction will be observed. This non-reaction is the immediate indicator of their properties.
This lack of attraction contrasts sharply with ferromagnetic metals like iron or steel, which possess internal magnetic domains that align themselves to be strongly pulled toward a magnet. Gold and silver lack this atomic structure and do not generate the strong magnetic moments required for an observable pull. Therefore, a pure item made of these precious metals will not stick to a magnet.
The Scientific Explanation: Understanding Diamagnetism
While not magnetic in the familiar sense, gold and silver possess a subtle property known as diamagnetism. Diamagnetic materials are characterized by a very weak repulsion from an external magnetic field. This property is present in all materials but is usually overpowered by stronger forms of magnetism.
The source of this weak repulsion lies in the electron configuration of the atoms. In both gold and silver, all electrons are paired, meaning there are no unpaired electrons to create a permanent magnetic moment. When an external magnetic field is applied, the field slightly distorts the orbital motion of these paired electrons, inducing a tiny magnetic field that opposes the external field.
This diamagnetic effect is so weak that it is virtually undetectable without specialized laboratory equipment. A powerful magnet placed near pure silver will not visibly push the metal away, though the subtle force is present at the atomic level. This behavior differs from paramagnetism, where materials like aluminum exhibit a weak attraction due to unpaired electrons aligning with the magnetic field.
The Importance of Purity: Testing for Impurities
The non-magnetic nature of pure gold and silver is the basis for a straightforward authenticity test used by jewelers and consumers. Since the pure metals do not attract a magnet, any noticeable magnetic attraction suggests the presence of other materials. This reaction is a quick way to screen for counterfeits or alloys containing ferromagnetic metals.
If a coin or jewelry strongly sticks to a magnet, it clearly indicates a significant amount of magnetic metal. Common impurities or base metals used in fakes, such as iron, nickel, or cobalt, are all highly ferromagnetic and are sometimes incorporated into alloys or used as core materials in plated items to reduce production costs.
While a magnet test quickly rules out fakes containing ferromagnetic materials, it is not a complete guarantee of purity. Some counterfeit items may be made from non-magnetic base metals like copper or aluminum, which will also not react to a magnet. Nevertheless, the magnetic test remains an effective first step, as a positive attraction instantly confirms the presence of a magnetic impurity, disqualifying the item as pure.