Melonite is a mineral that belongs to the pyrite group, and it is a rare iron sulfide mineral. Its chemical composition is Fe1-0.95Ni0.05S2, and it has a metallic luster and a steel-gray color. The mineral was named after the Greek word, melos, which means "limb" or "member," because it is commonly found as skeletal fragments in volcanic rocks. Melonite is also known as ferrous pyrite and nickel pyrite because it contains both iron and nickel in its chemical composition. It is not easy to find synonyms for melonite due to its rare occurrence, but some common synonyms include sulfide, pyrite, metallic mineral, and iron sulfide.