The value in rare earth magnets is their magnetic qualities, not the common materials from which hey are made. These magnets were developed in the 1970s and 1980s and have proven to be the strongest type of permanent magnets available. Magnets are rated by four different properties; their value depends upon the strength of the magnetism and how long it lasts. Two kinds of man-made magnets are widely used today because of these special properties. These are Samarium-cobalt and Neodymium.