Earth’s crust, which translates directly into the predominance of silicate minerals. Changes in the temperature, pressure, or bulk composition of a rock mass cause changes in its properties of aggregates pdf. Minerals can be described by their various physical properties, which are related to their chemical structure and composition.
Dana classification and the Strunz classification. In the simplest sense, this means the mineral must be solid. Modern advances have included extensive study of liquid crystals, which also extensively involve mineralogy. Minerals are chemical compounds, and as such they can be described by fixed or a variable formula.
The formal definition of a mineral approved by the IMA in 1995: “A mineral is an element or chemical compound that is normally crystalline and that has been formed as a result of geological processes. However, if geological processes were involved in the genesis of the compound, then the product can be accepted as a mineral. The first three general characteristics are less debated than the last two. Mineral classification schemes and their definitions are evolving to match recent advances in mineral science.
The IMA Commission on New Minerals and Mineral Names adopted in 2009 a hierarchical scheme for the naming and classification of mineral groups and group names and established seven commissions and four working groups to review and classify minerals into an official listing of their published names. According to these new rules, “mineral species can be grouped in a number of different ways, on the basis of chemistry, crystal structure, occurrence, association, genetic history, or resource, for example, depending on the purpose to be served by the classification. The distinction is a matter of classification and less to do with the constituents of the minerals themselves. Prior to the International Mineralogical Association’s listing, over 60 biominerals had been discovered, named, and published. 78 mineral classes listed in the Dana classification scheme. To date over 80,000 liquid crystalline compounds have been identified.
Unlike a true crystal, quasicrystals are ordered but not periodic. Minerals are not equivalent to rocks. The other minerals in the rock are termed accessory, and do not greatly affect the bulk composition of the rock. Overall, around 150 minerals are considered particularly important, whether in terms of their abundance or aesthetic value in terms of collecting. There are about 20 mineral species that qualify as gem minerals, which constitute about 35 of the most common gemstones. Minerals are classified by variety, species, series and group, in order of increasing generality.