Minerals
The easiest way that you know a mineral is something like a jewelry, material to the contruction, etc. But the correct definion is that A mineral is an element or chemical compound that is normally crystalline and that has been formed as a result of geological processes.

Nomenclature and classification
A mineral can be also narrowed down in terms of a mineral group, series, species, or variety, in order from most broad to least broad. The way that we can classify the minerals is watching the differences between the chemical and the physical properties.

Common classification
Dana calssification
This kind of calssification use the structure of a mineral in order to calssify the minerals.
Strunz classification
The less commonly used Strunz classification is based on the Dana system, but combines both chemical and structural criteria

Mineral chemistry
Mineral chemistry is the science that study chemical properties of the earth, where we can find in the earth and their abundance in the crust. For example oxygen, silicon, aluminium, iron, magnesium, calcium, sodium and potassium.These eight elements, summing to over 98% of the crust by weight, are, in order of decreasing abundance.

In nature, minerals are not pure substances, and are contaminated by whatever other elements are present in the given chemical system. As a result, it is possible for one element to be substituted for another.

Physical properties of minerals

A mineral can be identified by several physical properties, some of them being sufficient for full identification without equivocation.

Physical properties applied for classification include crystal structure and habit, hardness , lustre, diaphaneity, colour, streak, cleavage and fracture, and specific gravity

Crystal structure and habit

Crystal tructure results from the orderly geometric spatial arrangement of atoms in the internal estructure of a mineral.

Hardness

The hardness of a mineral defines how much it can resist scratching.

The most common scale of measurement is the ordinal Mohs hardness scale.

Colour

Colour is the most obvious property of a mineral, but it is often non-diagnostic. It is caused by electromagnetic radiation interacting with electrons.

Specific gravity

Specific gravity numerically describes the density of a mineral. The dimensions of density are mass divided by volume with units: kg/m3 or g/cm3. Specific gravity measures how much water a mineral sample displaces.