Iron disulfide (FeS2​) is a chemical compound composed of iron (Fe) and sulfur (S) atoms. It is commonly known as pyrite or “fool’s gold” due to its metallic luster and resemblance to gold. Pyrite is a naturally occurring mineral and has several interesting properties and uses:

1. Appearance: Pyrite has a brassy yellow color and often forms cubic or octahedral crystals. It can also occur as nodules or masses.
2. Mineral Specimen: Pyrite is a well-known mineral specimen and is often collected for its unique crystal forms and metallic appearance.
3. Geological Indicator: In geological contexts, pyrite can be an indicator of certain mineral deposits or mineralization processes. It is commonly associated with hydrothermal and magmatic ore deposits.
4. Sulfide Ore: Pyrite is a common sulfide mineral and is often found in association with other metal sulfides in ore deposits. While it has a metallic appearance, it does not contain significant amounts of valuable metals like gold.
5. Energy Production: Pyrite has been historically used as a source of sulfur in the production of sulfuric acid, a crucial chemical in many industrial processes. However, its use for this purpose has declined due to environmental concerns associated with acid mine drainage.
6. Crystal Structure: Pyrite has a crystal structure known as a cubic system. Its atomic arrangement gives rise to its distinctive cubic or octahedral crystal shapes.
7. Misidentification: Due to its golden color, pyrite has sometimes been mistaken for gold. However, gold is much softer and has a distinct metallic yellow color.
8. Metaphorical Use: The term “fool’s gold” is often used metaphorically to describe something that appears valuable but is ultimately worthless or deceptive.

While pyrite has several interesting properties and uses, it’s important to note that it doesn’t possess the same value as precious metals like gold or silver. It’s also important to handle pyrite with care, as it can produce sulfuric acid when exposed to oxygen and water, leading to potential environmental issues if it’s found in large quantities.