What are minerals and how are they formed?
Minerals are the essential elements that form rocks and they are present everywhere: from the ground we walk on to the objects we use every day.
To explain how they are formed, it is essential to understand what a mineral is. A mineral is a natural, inorganic substance with a defined chemical composition and an ordered crystalline structure.
They are solids that are formed by geological and chemical processes, which excludes substances produced by living organisms, such as plants or animals. Minerals come in various shapes and sizes, and their properties depend on both their chemical composition and their crystalline structure.
Minerals are essential to many industries and are used in the manufacture of a variety of products, from solar panels and cellular phones to electronic components. The great quantity and diversity of minerals present in the earth’s crust makes them an essential resource for the development of life as we know it.
There are several processes of mineral formation…
1- Magmatic Mineral Formations
The origin of many minerals is found in molten rock (magma) and lies within the Earth’s interior at temperatures between 650-1250 °C. In some cases, these liquid masses can rise to the surface, which causes them to cool as they rise.
During the early stages of this cooling, some minerals such as apatite or magnetite are formed. Then, as the temperature decreases further, most of the magma solidifies, forming minerals such as feldspars or quartz.
After this phase, there is still a small part of residual magma that is enriched with all the elements (such as boron, molybdenum, uranium, rare earth elements) that could not form part of the previous mineral structures, and the crystallisation of this residual magma produces other minerals.
2-Sedimentary Mineral Formations
Water transports dissolved materials eroded from rocks, such as salts or carbonates, until they are deposited in certain places. When this water evaporates, it causes the precipitation of the dissolved materials, which crystallise to form evaporitic rocks.
3- Metamorphic Mineral Formations
The last category consists of minerals that, although initially magmatic or sedimentary, pass through processes of change when exposed to high temperatures or pressures. This leads to a mechanism called metamorphism, where the crystalline structure of the mineral changes.
