What are Non-metallic Minerals? | Properties, Classification and Differences

Minerals are naturally occurring homogenous, solid substances of organic or inorganic origin with definite (but not fixed) atomic structures, physical properties and chemical compositions.

The earth contains within itself more than three thousand variety of minerals which are broadly classified into two types based on their chemical composition. Non-metallic minerals are one of those kinds.

Key Takeaways

1. Non-metallic minerals do not have metallic properties like malleability, ductility, and conductivity.
2. They are used in various industries like construction, ceramics, glass, and electronics.
3. Non-metallic minerals are classified based on their physical and chemical properties, and these classifications are essential for their commercial use.

Definition

An objective definition of Non-metallic minerals can be given not by describing ‘what they are’ but by outlining ‘what they are not. Accordingly, Non-metallic minerals are defined as minerals that do not contain any metallic content within themselves. 

In the periodic table, they are separated from the metals by a line that severs the table diagonally. Besides that, their structure mainly comprises of non-noble gases and halogens that are generally characterised by an ability to gain electrons quickly.

Properties of Non-Metallic Minerals

The following are some principal properties that distinguish Non-metallic minerals from Metallic minerals.

1.  They are made up of non-metallic elements.
2. They have a low boiling and melting point.
3. They are solid but have the potential to break easily.
4. They are poor conductors of electricity and heat.
5. They appear dull but can be bright in colour.
6. They are very receptive towards electrons.
7. Non-metallic minerals tend to have a high level of electronegativity. That is to say; they hold on to their existing electrons very firmly.

Classification of Non-metallic Minerals

Non-metallic Minerals can be classified in two ways:

1. Taking into account their nature of origin.
2. Taking into account the species of their content.

Based on Nature of Origin

Depending on their nature of origin, Non-metallic Minerals are classified into the following two types.

1. Organic: These are primarily fossil fuels, also called mineral fuels and are characterised by their genesis in the dead and buried remains of the plant and animal lives. For example, petroleum and coal.
2. Inorganic: These are derived from non-living matters—for example, mica, limestone, graphite etc. 

Based on the Species of their Content

Depending on the species of their content, Non-metallic Minerals can be classified into the following types:

1. Metallurgical auxiliary material. These include refractory clay, dolomite, silica, magnesite, fluorite etc.
2. Chemical non-metallic minerals. For example, sulfur, phosphorus, magnesium, potassium, ceresin, Glauber’s salt, trona. 
3. Ceramic and glass materials like feldspar, quartz sand, kaolin, plastic clay.
4. Building materials. These include marble, basalt, granite, gypsum.
5. ‘Special’ non-metallic minerals. For example, Iceland spar, mica, crystal, diamond, tourmaline and so on.
6. Other materials like pumice, asbestos, talc, diatomaceous earth, vermiculite and the like.

Advantages of Non-metallic Minerals

Non-metallic minerals constitute an integral part of our day to day life as most of the products we use are in some way or the other are made up of non-metallic minerals. Here are some significant benefits of non-metallic minerals:

1. They are crucial for the real-estate sector as most of the building materials like limestone are made up of non-metallic minerals.
2. The agriculture sector is highly dependent on non-metallic minerals as they are used for preparing fertilisers.
3. Non-metallic minerals like mica are used to manufacture electrical appliances and in the electronic industry.
4.  Non-metallic minerals do not require a substantial amount of processing or additional costs.

Disadvantages of Non-metallic Minerals

Despite their various benefits, Non-metallic minerals do suffer from some significant limitations.

1. They tend to brittle and hence, cannot be used for manufacturing sheets and wires.
2. No new product can be generated by melting Non-metallic minerals.

References

1. https://onlinelibrary.wiley.com/doi/abs/10.1111/jiec.12471
2. https://link.springer.com/chapter/10.1007/978-3-030-40268-6_10