Minerals

The Earth has been made of rock, rocks are made of minerals and minerals are made of atoms. For a better understanding of rocks, we should know minerals at first.

A mineral (is):

• Naturally Occurred/made
• Solid (it may not be found in the form of liquid or solid)
• Occurred with a certain chemical compound
• Has a crystal structure (atoms regularly placed next to one another forming the structure)

 

Some examples on minerals:

Is glass a mineral? Glass can be naturally Formed (the volcanic glasses are named Obsidian), a glass is solid contains given chemical compound, though it is not always the same, but because lacking a crystal structure (the atoms are randomly placed just like the position of atoms into a liquid), so that, glass is not a mineral.

Ice: Naturally formed, solid has a given chemical compound; H₂O; and a crystalline structure when it is in solid state. Therefore, ice is a mineral though water is not due to doesn’t have the crystal structure.

Halite; common salt: Naturally Formed, solid, with a given chemical compound: NaCl and crystal structure so that halite is a mineral.

 

THE LMPORTANT NINERALS OF EARTH

The variety of the minerals depends on the chemical elements according to their abundance in the crust of the Earth:

1. Oxygen: 45.5%
2. Silicon: 27.2%
3. Aluminium: 8.0%  
4. Iron: 5.8% 
5. Calcium : 5.1%     
6. Magnesium: 2.8%  
7. Sodium: 2.3%   
8. Potassium: 1.7%      
9. Titanium: 0.9%
10.  Hydrogen: 0.14%
11.  Manganese: 0.1%
12.  Phosphorous: 0.1%

Note that carbon (one of the most abundant elements in life) is not involved in the list.

Though there are limitations around 3000 minerals have been identified characterized, however, only 20-30 of this number are common and of higher importance. The most frequent / common minerals are the same which have been shaped through silicon & Oxygen: Silicates. The based silicates are Tetrahedron. It means that four atoms of Oxygen have surrounded one atom of silicate.

 

The forming of minerals

Minerals have been formed through varying phenomena, for example:

• ‍Crystallization is kind of event that leads to the formation of igneous rocks.
• Precipitation in the water: is the kind of event phenomenon that causes the formation of chemical sedimentary rocks.
• Shift into more stability: the phenomenon that produces the soil, through weathering & the formation of metamorphic rocks then.
• Precipitation of living- organisms / organisms: the event that causes the Biochemical sedimentary rocks to be formed.
•  Precipitation of gas: (it is not a very ordinary activity but something may be formed around the craters).

Different events cause different minerals to be shaped so that we can distinguish these events through characterizing the minerals.

In this case for identifying the minerals, we shall consider the diverse situations of pressure & temperature in which each mineral form in laboratory.

Some noteworthy minerals based on the above- mentioned factors

Now we draw your attention to 3 minerals witch are considered as the most important ones (more minerals will be introduced if necessary):

 

Quartz: crystalline silica, SiO2 is one the minerals that primarily & originally made out at acidic magma which is the producer at acidic rocks. Although quartz is originated within high temperatures, however, stable (not broken or altered) in conditions adjacent to the Earth's surface.

‍Clay minerals: clay minerals are phyllosilicates or sheet silicates, hence, have a crystalline structure through which  can be easily foliated along their sheets. This kind of minerals are produced by alteration of other minerals during the chemical weathering process (being altered under the conditions of earth's surface)  

Clay minerals are the main & basic ingredients through which soil is made and might be found within the sedimentary rocks such as shale and sandstone; as well.

Calcite: CaCo3 the stable from carbonate calcium, easily dissolved in the water with very low acid content. Organisms can absorb the ions of calcium & carbonate from water, storing them into their shells. Therefore, Calcite is one of the primary constituents at biochemical & chemical sedimentary rocks.