1. Naturally Occurring: Minerals are formed by natural geological processes, not created in a lab or by humans.
2. Inorganic: Minerals are not made of organic compounds (those containing carbon-hydrogen bonds). They are primarily composed of elements and their combinations.
3. Solid: Minerals exist in a solid state at room temperature.
4. Crystalline Structure: Minerals have a definite, repeating internal arrangement of atoms, ions, or molecules. This structure is responsible for their unique crystal forms.
5. Definite Chemical Composition: Each mineral has a specific chemical formula that can vary within a defined range. For example, quartz is always SiO2.
6. Homogeneous: Minerals are uniformly distributed throughout their structure. They don't have distinct parts or components.
Let's look at some examples to illustrate:
* Diamond: Naturally occurring, inorganic, solid, with a crystal structure and definite chemical composition (carbon).
* Salt (Halite): Naturally occurring, inorganic, solid, with a crystalline structure and definite chemical composition (NaCl).
* Ice: Naturally occurring, inorganic, solid, with a crystalline structure and definite chemical composition (H2O).
Things that are NOT minerals:
* Plastic: Man-made, organic, and lacks a crystalline structure.
* Wood: Organic, contains carbon-hydrogen bonds, and is not solid.
* Water: Liquid at room temperature (although frozen water as ice IS a mineral).
Important Note: Some substances can appear very similar to minerals but don't meet all the criteria. For example, obsidian is a naturally occurring, inorganic, solid, but lacks a crystalline structure (it's volcanic glass).