Why is coal not classified as a mineral?

Coal is not classified as a mineral in the same way that other minerals like quartz, feldspar, and mica are classified. The reason for this distinction lies in the way coal is formed and its composition.

Minerals are naturally occurring inorganic substances with a specific chemical composition and a crystalline atomic structure. They are typically formed through geological processes and have well-defined physical and chemical properties. Coal, on the other hand, is primarily composed of organic matter and is formed from the remains of plant material that underwent various stages of decomposition over millions of years. It does not have a crystalline atomic structure and is not considered an inorganic substance.

While coal does contain some inorganic components, such as minerals and mineraloids that were present in the original plant material or introduced during the coal formation process, its predominant composition is organic. This organic composition sets coal apart from minerals in the traditional geological sense.

In summary, coal's organic origin and lack of a crystalline structure are the main reasons why it is not classified as a mineral like other inorganic substances found in the Earth's crust.