What are Minerals? – A mineral is a naturally occurring substance that is solid and stable at room temperature, representable by a chemical formula, usually abiogenic, and has an ordered atomic structure.
- Minerals are naturally occurring substances formed by geological processes. They are usually solid and feature a crystal structure as well as specific physical properties and chemical composition.
- Physical properties of minerals include crystal structure, hardness (Mohs scale), lustre (how it reflects light) and color, as well as more complicated properties such as streak, fracture, cleavage and density.
- Mohs scale of hardness measures the ability of minerals to scratch each other. Talc is very soft and is listed as 1, diamond is very hard and is measured as 10.
- A mineral is sometimes made up of just one chemical element but more often it is a compound (mixture) of two or more.
- For example, diamond is made up of just carbon, while fluorite is made up of a compound of calcium and fluorine.
- There are over 4000 different types of minerals.
- Only around 30 of these are commonly found in the Earth’s crust.
- Examples of minerals include calcite, gypsum, feldspar, pyrite, gold, quartz and diamond.
- The precious gems ruby and sapphire are varieties of the mineral corundum.