An intermetallic or iron aluminide magnetically readable medium and a method of forming and reading the same are provided herein. Also provided is an identification card or tag, a key, an anti-counterfeiting measure, an anti-forging measure. The intermetallic or iron aluminide magnetically readable medium includes a magnetically readable surface, wherein the magnetically readable surface contains one or more first magnetically readable regions of the intermetallic or iron aluminide surrounded by one or more second magnetically readable regions. Additionally, the intermetallic or iron aluminide magnetically readable medium can be coated, encapsulated or concealed within a material.