Marcasite is a mineral that is composed of iron sulfide and has a pale yellow to almost white color. It is often used as a gemstone in jewelry due to its metallic luster and unique crystal structure. Marcasite is also commonly found in sedimentary rocks and can be used in industrial processes, such as in the production of sulfuric acid. However, it is not as widely used as its similar-looking cousin, pyrite, due to its tendency to deteriorate into a powdery substance over time.
