Rautadisulfidi

Rautadisulfidi, also known as iron(III) disulfide or pyrite, is an iron sulfide mineral with the chemical formula FeS2. It is the most common sulfide mineral on Earth and is found in a wide variety of geological environments, including igneous, metamorphic, and sedimentary rocks. Pyrite is characterized by its pale brass-yellow color and its metallic luster, often leading to it being mistaken for gold, hence its nickname "fool's gold." The crystal structure of pyrite consists of iron cations (Fe2+) and disulfide anions (S22−). It typically crystallizes in the isometric system, often forming cubic, octahedral, or pyritohedral crystals, and can also occur in massive, granular, or botryoidal forms.

Pyrite is relatively hard, with a Mohs hardness of 6 to 6.5, and brittle. It has a high specific gravity, around 4.9 to 5.2. While generally stable, pyrite can oxidize in the presence of air and moisture to form iron oxides and sulfates, a process known as pyrite weathering or acid mine drainage when it occurs in mines. Historically, pyrite was used as a source of sulfur dioxide for the production of sulfuric acid, a crucial industrial chemical. It has also been used as a gemstone and in the manufacture of some types of fireworks. In modern times, its primary significance is as an indicator mineral in geological studies and as a potential source of valuable elements when present in certain ore deposits.