Appearance
Pyrite is a light brass-yellow color, often with a yellowish-brown tint. It has a metallic luster, is opaque, and is quite hard, with a Mohs hardness of 6-6.5. Its crystals vary in morphology, with cubes, octahedra, and pentagonal dodecahedrons being common, and sometimes even complex aggregates occur. Due to its unique appearance, it was mistaken for gold in ancient times, earning it the nickname "fool's gold."
Chemical Composition
Pyrite is composed of ferrous disulfide (FeS₂). It is a compound of iron and sulfur, with an iron content of 46.55% and a sulfur content of 53.45%. This chemical composition gives pyrite its unique physical and chemical properties.
Physical Properties
Pyrite has a high density of approximately 4.9-5.2 g/cm³. Its good electrical and thermal conductivity makes it potentially useful in various electronic and electrical applications. Pyrite also exhibits incomplete cleavage, resulting in a jagged fracture. Its streak is greenish-black, and it is brittle and easily shattered when subjected to external forces.
Chemical Properties
Pyrite is relatively stable in air, but at high temperatures it reacts with oxygen to produce iron oxide and sulfur dioxide. This reaction is used industrially to produce sulfuric acid, making it a key raw material for sulfuric acid production. Pyrite can also react with some acids to release hydrogen sulfide gas.