Mineralogy and its scope - Mineral Science |Geologypage

Mineralogy and its scope

Mineralogy is the branch of Geology which deals with the study of minerals. This is further divided into physical and chemical mineralogy. Physical mineralogy deals with a set of diagnostic physical properties such a color, streak, luster, hardness, specific gravity and external form or shape. On the other hand chemical mineralogy deals with the understanding of the principles that govern the chemical composition of minerals, expressed by a chemical formula.

Quartz crystals

What is a mineral?
A mineral is defined as a naturally occurring homogeneous solid, inorganically formed, with a definite chemical composition and an ordered internal atomic structure. Some  common examples are quartz, feldspar, diamond.

Now-a-days minerals can also be produced in laboratory, for example Halite can be formed by evaporating a solution of sodium chloride. Similarly many gem stones are also produced synthetically and these minerals are known as synthetic minerals.

From the definition of mineral, you can have an idea that, a mineral has to be a homogeneous solid, which means liquid and gases are not minerals. For example water is not a mineral but ice is considered a mineral. (what do you think ?). Secondly, it has to form inorganically to be considered a mineral, that implies homogenous solid formed by plants and animals are not considered as minerals. Again the requirement of a definite chemical composition means that a mineral does not have a fixed composition since its chemical formula may vary within the limits.

What is a mineraloid?

There are some naturally occurring minerals that lack definite atomic structure or chemical composition, these are known as mineraloids. Opal is a good example of mineraloid.

Scope of mineralogy

Since the beginning of 20^th century, the scope of mineralogy has changed considerably from a merely descriptive discipline to a highly innovative field of science by incorporating ideas, techniques, and aspects of many neighboring areas such as physics, chemistry, material science, biology, archeology, and medicine. Modern mineralogy seeks to understand the links among mineral structure, properties, and processes in a range of potentially technologically useful solids. The constant requirement of human societies for new materials, ranging from building materials to pharmaceuticals, acted as a driving force for the diversity of mineralogical research and finally led to the innovations of the mineralogical sciences permeating many aspects of our daily life.

Further reading/ references : Textbook of mineralogy - E.S DANA

Mineralogy - L.G Berry & B. Mason

Crystallography & mineralogy - R.S. Sharma & A Sharma

Image courtesy- geologyrocksandminerals

Video courtesy- agta_gems and amethystsky11_deals