A friend recently gave me an earth magnet to test silver coins. I understand HOW to use it, but does anyone know how it works? US coins are made from nonferrous metals that would not attract a magnet. So why does the magnet slow down when going down a genuine silver coin? Curiosity has struck me after recently studying the laws of electromagnetism.
Atoms can show 3 types of response to a magnetic field. Ferromagnetism and paramagnetism are stronger than diamagnetism ( what we are discussing with silver and other heavy metals with certain electron arrangement. Diamagnetism is usually so weak , it plays no important role in magnetism response, but in these metals and other substances such as wood and some plastics , that are normally ( by non-scientists) considered non-magnetic, the diamagnetic force is mathematically more than the other 2 forms, and the diamagnetic material is repelled by the magnetic force applied rather than attracted to it. But it is a weak force, and many try to show it in precious metal by sliding the metal down a slope and see if a very strong magnet can repel its direction slightly. Your mileage may vary.
Well irrelevant to the question but the only US coin that ever attracted to a magnet was a 1943 wheat penny... but yea I don't really understand the silver magnet thing
Pure nickel is STRONGLY magnetic, but it loses most of its magnetic properties when alloyed with as little as 8 - 10% of other metals.
