* Organic: Minerals are inorganic, meaning they are not derived from living organisms. For example, coal (formed from decomposed plants) and amber (fossilized tree resin) are not minerals.
* Man-made: Minerals form naturally through geological processes. Materials created by humans, like steel, glass, or plastic, are not considered minerals.
* Amorphous: Minerals have a defined, ordered internal structure (crystalline structure). Substances like obsidian (volcanic glass) and opal (amorphous silica) lack this structure and are not minerals.
* Variable Composition: While some minerals can have slight variations in their chemical composition, they generally have a specific formula. For example, quartz (SiO₂) is a mineral, but a rock like granite has variable amounts of quartz, feldspar, and mica.
* Liquid or Gaseous State: Minerals are solid. Water, oil, and natural gas are not minerals.
Remember: The defining characteristics of a mineral are:
1. Naturally Occurring: Formed by geological processes.
2. Solid: Has a definite shape and volume.
3. Inorganic: Not derived from living organisms.
4. Crystalline Structure: Has a defined, ordered internal structure.
5. Specific Chemical Composition: Generally has a fixed chemical formula.
